1. Field of the Invention
The present application is related to delivery of multimedia educational content and, in particular, to techniques for determining compensation metrics (e.g., for originators and/or sponsors of educational content) in correspondence with determinations of student populations for which student identity is reliably authenticated in the course of interactive submission of, or participation in, coursework.
2. Description of the Related Art
As educational institutions seek to serve a broader range of students and student situations, on-line courses have become an increasingly important offering. Indeed, numerous instances of an increasingly popular genre of on-line courses, known as Massive Open Online Courses (MOOCs), are being created and offered by many universities, as diverse as Stanford, Princeton, Arizona State University, the Berkeley College of Music, and the California Institute for the Arts. These courses can attract tens (or even hundreds) of thousands of students each. In some cases, courses are offered free of charge. In some cases, courses are offered for credit.
While some universities have created their own Learning Management Systems (LMS), a number of new companies have begun organizing and offering courses in partnership with universities or individuals. Examples of these include Coursera, Udacity, and edX. Still other companies, such as Moodle, offer LMS designs and services for universities who wish to offer their own courses.
Students taking on-line courses typically watch video lectures, engage in blog/chat interactions, and submit assignments, exercises, and exams. Submissions may be evaluated and feedback on quality of coursework submissions can be provided. In some cases, new educational business models are possible. To facilitate these new business models, technological solutions are needed. For example, in some cases, improved techniques are needed for reliably ascertaining or authenticating identity of a student user submitting assignments, exercises, and exams. In some cases, improved metrics are desired to facilitate compensation of originators and/or sponsors of educational content in a manner that reliably corresponds to actual subscribed and/or for-credit participation in the on-line coursework.
It has been discovered that high-quality multimedia content of on-line course offerings can be made available to users on both a free-of-direct-charge basis and on a fee-bearing subscription, member or for-credit basis, while providing a revenue split with originators and/or sponsors of educational content. In general, such compensation models rely on computational techniques that reliably authenticate the identity of individual student users during the course of the very submissions and/or participation that will establish student user proficiency with course content.
In some embodiments in accordance with the present invention(s), a method includes (1) providing multimedia educational content to users in an internetworking environment; (2) authenticating identity of individual users at least in part by computationally processing key sequence timings captured in connection with passphrase responses unique to the individual users, wherein the passphrase for a particular individual user is structured to include key sequences for which timings were computationally determined to be characteristic of the particular user; and (3) determining compensation for either or both of contributors and sponsors of the provided educational content based at least in part on a compensation metric that is based on population of users whose identity has been authenticated at least in part by the computational processing of the key sequence timings.
In some embodiments in accordance with the present invention(s), a method includes (1) providing multimedia educational content to users in an internetworking environment, the multimedia educational content including coursework requiring, at least for a subset of the users, interactive responses; (2) authenticating identity of individual users at least in part by computationally processing audio features extracted from user vocals captured in connection with the interactive responses; and (3) determining compensation for either or both of contributors and sponsors of the provided educational content based at least in part on a compensation metric that is based on population of users whose identity has been authenticated at least in part by the computational processing of the audio features.
In some embodiments in accordance with the present invention(s), a method includes (1) providing multimedia educational content to users in an internetworking environment, the multimedia educational content including coursework requiring, at least for a subset of the users, interactive responses; (2) authenticating identity of individual users at least in part by computationally processing image processing features of images or video of the individual users captured in connection with the interactive responses; and (3) determining compensation for either or both of contributors and sponsors of the provided educational content based at least in part on a compensation metric that is based on population of users whose identity has been authenticated at least in part by the computational processing of the image processing features.
In some embodiments in accordance with the present invention, a method includes a method includes (1) providing multimedia educational content to users in an internetworking environment, the multimedia educational content including coursework requiring, at least for a subscribing subset of the users, interactive responses from the users; (2) authenticating identity of individual users from the subscribing subset of users at least in part by computationally processing at least one of (i) key sequence timings captured in connection with the interactive responses by the individual users, (ii) audio features extracted from user vocals captured in connection with the interactive responses and (iii) image processing features of images or video of the individual users captured in connection with the interactive responses; and (3) determining compensation for either or both of contributors and sponsors of the provided educational content based at least in part on a compensation metric that is based on population of users, from the subscribing subset thereof, whose identity has been authenticated at least in part by the computational processing of the key sequence timings, the captured audio features or the images or video captured in connection with the interactive responses.
In some cases or embodiments, the population of users on which the compensation metric is based is a set of users determined, at least in part based on the interactive responses, to be active users. In some cases or embodiments, the population of users on which the compensation metric is based excludes those users determined to be inactive.
In some embodiments, the method further includes determining the active set of users based on one or more of: submission of assignments by the user, completion of quizzes or tests, and participation in user forums.
In some cases or embodiments, the compensation metric includes allocation of a predetermined non-zero share of member or subscription fees to the contributors or sponsors of the provided educational content with respect to which a particular user is determined to be active. In some cases or embodiments, the compensation metric includes allocation of a predetermined non-zero share of fees to the contributors or sponsors of the provided educational content with respect to which a particular user is registered for credit.
In some cases or embodiments, the identity authenticating includes computationally evaluating correspondence of the captured key sequence timings with key sequence timings previously captured for, and previously determined to be, characteristic of a particular user. In some embodiments, the method further includes capturing the key sequence timings for the particular user and computationally determining particular ones of the key sequence timings to be characteristic of the particular user. In some cases or embodiments, the key sequence timing capture is performed, at least in part, as part of enrollment of the particular user. In some embodiments, the method still further includes creating a passphrase for the particular user, wherein the created passphrase is structured to include key sequences for which timings were computationally determined to be characteristic of the particular user.
In some cases or embodiments, the identity authenticating includes computationally evaluating correspondence of the captured vocal features with vocal features previously captured for, and previously determined to be, characteristic of a particular user. In some embodiments the method further includes capturing the vocal features for the particular user and computationally determining particular ones of the vocal features to be characteristic of the particular user. In some cases or embodiments, the vocal feature capture is performed, at least in part, as part of enrollment of the particular user.
In some cases or embodiments, the identity authenticating includes computationally evaluating correspondence of the captured image processing features with features previously captured for, and previously determined to be, characteristic of a particular user. In some embodiments, the method further includes capturing the image processing features for the particular user and computationally determining particular ones of the image processing features to be characteristic of the particular user. In some cases or embodiments, the image processing feature capture is performed, at least in part, as part of enrollment of the particular user.
In some embodiments, the method still further includes providing the particular user with an on-screen game or task and during the on-screen game or task capturing the image processing features. The on-screen game or task provides a user interface mechanism by which movement, by the particular user, of his or her face within a field of view of visual capture device is used to advance the particular user through the on-screen game or task.
In some cases or embodiments, the identity authentication is multi-modal. In some embodiments the method further includes computationally evaluating correspondence of at least some of the captured image processing features with captured vocals.
In some cases or embodiments, the compensation metric allocates either or both of member/subscription fees and tuition. In some cases or embodiments, the contributors include educational content originators and/or instructors. In some cases or embodiments, the sponsors include educational institutions, testing organizations and/or accreditation authorities. In some embodiments, the method further includes compensating either or both of the contributors and sponsors based on the determined compensation metric.
In some cases or embodiments, a computational system including one or more operative computers is programmed to perform at least one of the preceding methods. In some cases or embodiments, the computational system is embodied, at least in part, as a network deployed coursework submission system, whereby a large and scalable plurality (>50) of geographically dispersed students may individually submit their respective coursework submissions in the form of computer readable information encodings. In some cases or embodiments, a non-transient computer readable medium encodes instructions executable on one or more operative computers to perform at least one of the preceding methods.
In some embodiments in accordance with the present invention(s), a learning management system includes one or more multimedia educational content stores, a biometrically-based user authentication mechanism and an administration module. The one or more multimedia educational content stores are network-accessible and configured to serve a distributed network-connected set of content delivery devices with multimedia educational content including interactive content requiring, at least for a subscribing subset of the users, interactive responses. The biometrically-based user authentication mechanism is configured to authenticate identity of individual users from the subscribing subset of users at least in part by computationally processing one or more of (i) key sequence timings, (ii) audio features extracted from user vocals and (iii) image processing features of images or video of the individual users, each captured, for a respective user from the subscribing subset of users, at a respective content delivery device in connection with the interactive responses by the respective user to the multimedia educational content served from the network-accessible content stores. The administration module is configured to maintain records data for individual users from the subscribing subset of users and coupled to receive from the biometrically-based user authentication mechanism indications that, in the course of interactive responses by respective users to the multimedia educational content served from the network-accessible content stores, particular users from the subscribing subset of users have been authenticated. The administration module is further configured to determine compensation for either or both of contributors and sponsors of the served educational content based on a compensation metric that is based at least in part on an active population of users, from the subscribing subset thereof, whose identity has been authenticated at least in part by the computationally processing of the key sequence timings, the captured audio features or the images or the video captured in connection with the interactive responses.
The present invention(s) are illustrated by way of example and not limitation with reference to the accompanying drawings, in which like references generally indicate similar elements or features.
The solutions described herein address problems newly presented in the domain of educational coursework, administration and testing, such as for on-line courses offered for credit to large and geographically dispersed collections of students (e.g., over the Internet), using technological solutions including computational techniques for feature extraction and student user authentication based on captured features of student responses to interactive content. In some cases or embodiments, timing of keystroke sequences captured in the course of typed responses and/or computationally-defined audio (e.g., vocal) and/or image/video (e.g., facial) features captured via microphone or camera may be used to reliably authenticate identity of a student user. In this way, coursework submissions (e.g., test, quizzes, assignments, participation in class discussions, etc.) may be auto-proctored in a manner that allows sponsoring institutions to provide or assign credit and credence to student performance.
We envision on-line course offerings that are available to users on both (1) a free-of-direct-charge basis and (2) a fee-bearing subscription, member or for-credit basis. In general, student-users can avail themselves of university-level, credit-granting courses online. They can watch the lectures for free. In some cases, student-users can even do the assignments and participate in the discussion forums. However, if they want their assignments graded and/or if they want other premium benefits, a member/subscriber tier is available.
Premium benefits can include instructor- or teaching assistant-based feedback on coursework submissions, member or “for-credit” student status in discussion forums, discounts on software, hardware, text books, etc. In some cases, premium member/subscriber tier benefits may include the reporting of a verifiable level of achievement to an employer or university (e.g., John Q. Student finished 5th, or in the 5th percentile, in Introduction to Multiplayer Game Development and Coding, offered by a particular and prestigious university) or as a certification mark for an on-line resume, professional networking site or job-recommendation service.
Member/subscriber tier premium benefits may, in some cases, include the ability to take course(s) for actual university credit, even as a high-school student or younger. As a result, and in some cases, Advanced Placement courses, exams, and credit start to look less attractive in comparison to actual credit that can transfer into or across schools.
For at least some of these premium services, technological solutions are needed or desirable to implement the membership system, to auto-proctor coursework submissions and reliably authenticate identities of users in the course of coursework submissions and/or class participation. Preferably, biometrically-based authentication techniques are used to reduce risks of student impersonators and “hired-gun” or proxy test taker schemes to procure credit. Due to the interactive nature of coursework submissions and class participation, and due to the general absence of practical physical location and physical presence based proctoring options for on-line courses, we tend to emphasize biometrics that can be captured from or extracted from actual coursework submissions and/or on-line class participation. For example, computational processing of:
Note that in many cases and implementations, in addition to the member/subscriber tier premium benefits provided to authenticable users, unauthenticated “auditing” of course content may also (and typically will) be provided, though not for credit, employer reporting, certification, etc. In some cases, authenticated member/subscriber tier users may be offered the opportunity to “wait-and-see” how they perform, before requesting actual university credit, employer reporting or certification.
Building on a biometrically-based authentication infrastructure, new revenue models and compensation metrics for originators and/or sponsors of educational content have been developed. For example, in some embodiments, compensation metrics for originators and/or sponsors of educational content are determined as a function of user populations for which identity is reliably authenticated in the course of interactive submission of, or participation in, coursework. For example, in some cases, at the end of a period (year, semester, etc.), we do an accounting of how many member/subscriber tier users were active in each course. Revenue is distributed and/or split based on the active user base.
In general, users cannot just watch videos to be “active.” Instead, multimedia lesson content typically will include quizzes or other coursework requiring interactive responses. Quizzes and other coursework are typically embedded in a lesson or presented between lessons. In some cases, automated grading technology tracks student progress, possibly not letting a student progress to the next lesson/video until he or she has proven some level of mastery by way of interactive responses. In some cases the system may simply require the user to demonstrate that he or she has paid attention, again by way of interactive responses. In each case, features captured or extracted from the interactive responses (or at least from some of the interactive responses) may be computationally evaluated for correspondence with biometrics characteristic of the member/subscriber tier user that the student purports to be.
In general, member/subscriber tier users participating for credit must complete the assignments, finish the course, and possibly even participate in user forums. Although different implementations may employ different completion criteria, on balance, many implementations will seek to achieve some balance between ensuring that interested students are retained and assuring sponsoring institutions both that the retained active students really participated in their course(s) and that, for each such active student, his/her identity has been reliably authenticated throughout interactive submissions (including graded quizzes, test and other coursework). For credit, criteria typically include completion of all the interactive response requiring coursework/assignments and demonstrating target levels of proficiency by way of interactive quizzes and/or exams. For member/subscribing users not participating for credit, some lesser set of criteria may be employed.
Based on the active user population data analytics, we pay out a revenue split to each sponsoring institution and/or each instructor (or other content originator). Typically, revenue splits are calculated after backing out per-member/participant expenses, although any of a variety of expense allocations is possible. In general, a revenue base may include member/subscription fees, a portion of revenue from purchases of software, hardware, text books, etc., value-added services such as grading/feedback for supplemental content or exercises, even advertising revenue. In the case of active users for-credit, tuition and related fees may be included in a revenue base.
Although any of a variety of revenue splits may be desirable or negotiated based on quality of educational content, the compensation metrics are anchored in the population of active users, where active users are reliably authenticable based on biometric information captured or extracted during the course of the very submissions and/or participation that establish student user proficiency with course content. In this way, fraud risks are greatly reduced. In addition, the use of authenticated active user based metrics for compensation of originators and/or sponsors of educational content tends to incentivize creators and sponsors of quality educational content and monetize member/subscriber tier premium services, all while managing and preserving a free-access model for a subset of the user base.
Automated coursework evaluation subsystem 221 includes a training/courseware design component 122 and a coursework evaluation component 123. An instructor and/or curriculum designer 202 interacts with the training/courseware design component 122 to establish (for given coursework such as a test, quiz, homework assignment, etc.) a grading rubric (124) and to select related computationally-defined features (124) that are to be used to characterize quality or scoring (e.g., in accordance with criteria and/or performance standards established in the rubric or ad hoc) for coursework submissions by students.
For example, in the context of an illustrative audio processing assignment, a rubric may define criteria including distribution of audio energy amongst selected audio sub-bands, degree or quality of equalization amongst sub-bands, degree of panning for mixed audio sources and/or degree or quality of signal compression achieved by audio processing. In the context of an illustrative image or video processing assignment, a rubric may define criteria for tonal or chromatic distributions, use of focus or depth of field, point of interest placement, visual flow and/or quality of image/video compression achieved by processing. Based on such rubrics, or in accord with ad hoc selections by instructor and/or curriculum designer 202, particular computationally-defined features are identified that will be extracted (typically) based on signal processing operations performed on media content (e.g., audio signals, images, video, digitized 3D surface contours or models, etc.) and used as input feature vectors in a computational system implementation of a classifier. Instructor and/or curriculum designer 202, also supplies (or selects) media content exemplars 126 and scoring/grading 127 thereof to be used in classifier training 125.
In general, any of a variety of classifiers may be employed in accordance with statistical classification and other machine learning techniques that exhibit acceptable performance in clustering or classifying given data sets. Suitable and exemplary classifiers are identified herein, but as a general proposition, in the art of machine learning and statistical methods, an algorithm that implements classification, especially in concrete and operative implementation, is commonly known as a “classifier.” The term “classifier” is sometimes also used to colloquially refer to the mathematical function, implemented by a classification algorithm that maps input data to a category. For avoidance of doubt, a “classifier,” as used herein, is a concrete implementation of statistical or other machine learning techniques, e.g., as one or more of code executable on one or more processors, circuitry, artificial neural systems, etc. (individually or in combination) that processes instances explanatory variable data (typically represented as feature vectors extracted from instances of data) and groups the instances into categories based on training sets of data for which category membership is known or assigned a priori.
In the terminology of machine learning, classification can be considered an instance of supervised learning, i.e., learning where a training set of correctly identified observations is available. A corresponding unsupervised procedure is known as clustering or cluster analysis, and typically involves grouping data into categories based on some measure of inherent statistical similarity uninformed by training (e.g., the distance between instances, considered as vectors in a multi-dimensional vector space). In the context of the presently claimed invention(s), classification is employed. Classifier training is based on instructor and/or curriculum designer inputs (exemplary media content and associated grading or scoring), feature vectors used characterize data sets are selected by the instructor or curriculum designer (and/or in some cases established as selectable within a training/courseware design module of an automated coursework evaluation system), and data sets are, or are derived from, coursework submissions of students.
Based on rubric design and/or feature selection 124 and classifier training 125 performed (in training/courseware design component 122) using instructor or curriculum designer 202 input, feature extraction techniques and trained classifiers 128 are deployed to coursework evaluation component 123. In some cases, a trained classifier is deployed for each element of an instructor or curriculum designer defined rubric. For example, in the audio processing example described above, trained classifiers may be deployed to map each of the following: (i) distribution of audio energy amongst selected audio sub-bands, (ii) degree or quality of equalization amongst sub-bands, (iii) degree of panning for mixed audio sources and (iv) degree or quality of signal compression achieved by audio processing to quality levels or scores based on training against audio signal exemplars. Likewise, in the image/video processing example described above, trained classifiers may be deployed to map each of the following: (i) distribution of tonal or chromatic values, (ii) focus or depth of field metrics, (iii) positioning or flow with a visual field of computationally discernible points/regions of interest and (iv) degree or quality of image/video compression to quality levels or scores based on training against image or video content exemplars. In some cases, features extracted from media-rich content 111 that constitutes, or is derived from, coursework submissions 110 by students 201 are used as inputs to multiple of the trained classifiers. In some cases, a single trained classifier may be employed, but more generally, outputs of multiple trained classifiers are mapped to a grade or score (129), often in accordance with curve specified by the instructor or curriculum designer.
Resulting grades or scores 130 are recorded for respective coursework submissions and supplied to students 201. Typically, coursework management system 120 includes some facility for authenticating students, and establishing, to some reasonable degree of certainty, that a particular coursework submission 110 is, in fact, submitted by the student who purports to submit it. Student authentication may be particularly important for course offered for credit or as a condition of licensure.
In some embodiments of coursework management system 120 (see e.g.,
While neither automated coursework evaluation, nor media-rich coursework such as described above, are essential in all cases, situations or embodiments in accord with the present invention(s), the above-described techniques are illustrative of techniques employed in at least some embodiments. Additional techniques are detailed in commonly-owned, co-pending U.S. application Ser. No. 14/461,310, filed 15 Aug. 2014, entitled “FEATURE EXTRACTION AND MACHINE LEARNING FOR EVALUATION OF IMAGE- OR VIDEO-TYPE, MEDIA-RICH COURSEWORK” and naming Kapur, Cook, Vallis, Hochenbaum and Honigman as inventors , the entirety of which is incorporated herein by reference.
In general, any of a variety of biometrically indicative responses 311 may be employed by respective feature extraction and classification computations 350 to train (354) respective classifiers 350 and thereafter authenticate identify (311) of a student user. The set and usage (including, in some cases or embodiments, for multi-modal authentication) of particular features and classifiers is, in general, implementation dependent; however, in the illustrated implementation, features are extracted from one or more biometrically indicative responses 311 and processed using one or more of audio feature extraction and classification 351, image/video feature extraction and classification 352 and/or keystroke timing feature extraction and classification 353. Training (354) can be performed as part of a student enrollment process and/or during course administration. Resulting indicative data is stored (312) in biometric/authentication data store 341 for subsequent retrieval (312) and use in authentication.
Sets of computational features extracted from biometrically indicative responses 311 and particular classification techniques employed to authenticate identity (313) of a particular user are each described in greater detail below. Such authentication may be multi-modal in nature, as described in commonly-owned, co-pending Provisional Application No. 62/000,522, filed May 19 2014, entitled “MULTI-MODAL AUTHENTICATION METHODS AND SYSTEMS” and naming Cook, Kapur, Vallis and Hochenbaum as inventors, the entirety of which is incorporated herein by reference. On the other hand, multimodal techniques need not be employed in all cases, situations or embodiments, and single mode authentication of identity (313), e.g., based simply on audio feature extraction and classification 351, or image/video feature extraction and classification 352 or keystroke timing feature extraction and classification 353, may be desirable and effective in some embodiments. However, for purposes of descriptive context and without limitation, each such modality is illustrated in
Also illustrated in
On the other hand, in some cases, situations or embodiments, interactive responses (be they typed, voiced or based on image/video capture) may be in response to a more overt authentication request, such as:
Based on coursework or non-coursework responses and particular feature extraction and classification techniques employed, student authentication subsystem 222 uses the biometrically indicative responses 311 to authenticate identity (313) of a particular student user so that coursework submissions by that student user and grades or scores attributable thereto may be appropriately credited. For purposes of illustration, a separate lookup (314) of student data in a separate course data store 342 is shown, although in some implementations, a combined database or store may be employed. Based on the authenticated identity (313) and on course data 342 maintained for a user whose identity has been authenticated, it is possible to determine (e.g., by student type lookup) whether the particular user (i) is enrolled for credit with a particular sponsoring institution or body, (ii) is a member or subscriber, or (iii) is merely auditing the course (or a unit thereof) as part of an open, non-fee-bearing enrollment. Note that, in some cases, situations or embodiments, a user auditing or participating as part of an open, non-fee-bearing enrollment, need not even be authenticated, and users who fail to authenticate may simply be treated as such.
As illustrated in
For example, in the case of a user who has been reliably authenticated as a participant for credit at a sponsoring educational institution, revenue may be allocated amongst (i) the sponsoring educational institution, (ii) an originator (or originators) of the particular course (e.g., an author, professor/instructor and/or curriculum designer) and (iii) an on-line content or courseware provider in accordance with a first allocation (perhaps 45%, 5%, 50%). On the other hand, for another user who has been authenticated (while participating in the very same course) as a member participating under a membership agreement with, for example, the on-line content or courseware provider, a second allocation (perhaps 20%, 5%, 75%) may be used. Free auditing by still other users may, and typically is, also provided without revenue allocation. In general, the particular shares or allocations of revenue and, indeed, particular participants in any such revenue allocation (323) are matters of negotiation and business choice.
Turning next to
Phase 2 deals primarily with aligning and cropping the image for consistency and to establish a region of interest (ROI) within the captured image. First, the image is cropped (crop 1, 405) around the detected face region (that determined in phase 1 and containing the face contour), and stored (406) for later use. A facial landmark detector (407) determines areas of interest in this region (eyes, nose, mouth, etc.) and their positions are used to make a tighter crop region inside the face. One suitable implementation of facial landmark detector 407 employs a flandmarks algorithm available open source for facial landmark detection, though alternative implementations may employ active appearance models (AAMs), active shape models ASMs, or Viola-Jones Haar cascades for facial landmark detection. Using this facial landmark defined region (crop 2, 408), a focus measure can be calculated (409) to measure blurriness of the facial region of the image. If this region fails to pass a focus threshold check (410), another image capture is attempted and the process is retried for the newly captured image, beginning with phase 1. However, if image focus is acceptable (or if pruning based on a focus threshold violation is disabled), a sharpening filter is applied to subtly sharpen the image and improve contrast in facial features and contours.
Next, the angle between the eyes (determined from the center of each eye interpolated from the eye corners detected using the facial landmark detector) is calculated and used to rotate (412) the image for frontal pose alignment. Additionally, in some implementations, a low-pass (LP) smoothing filter is employed on the eye locations as facial landmark detection is used to recalculate landmarks within each frame, without incorporating the previously calculated facial landmark positions. Next, the image is scaled (413) and cropped (414), based on the (recalculated) facial landmarks. Lastly, additional illumination processing (415, using a Tan-Triggs technique) is applied to reduce the impact of variable illumination in the image and environment. Phase 2 processing seeks to achieve sufficient alignment, scale and illumination consistency between images captured and processed for different subjects to support phase 3 recognition.
When performed as part of a user enrollment or training mode, the result of phase 2 processing is stored in library 416 for use in subsequent identity authentication in the course of coursework submissions. When performed as part of identity authentication in the course of coursework submissions, further processing seeks to recognize the result of phase 2 processing based on the stored library of images.
Lastly, phase 3 recognition (417) attempts to recognize the face against trained images in library 416 of biometric/authentication data store 341 (recall
As part of enrollment 501, the user enters (511) textual content, e.g., as part of user profile entry or in response to some direction from coursework management system 120. Web-based application code executing locally at the user's workstation (e.g., workstation 101, recall
Turning now to
Key pairs and their features are collected in the following manner. The alphabet, numbers, space, shift, and commonly used punctuation keys are tracked. Pairs containing untracked keys may be disregarded by the analyzer. Pairs are stored in a KeyPair data structure 701, such as that illustrated in
Two buffers are used in the process of key collection: one for storing incomplete KeyPairs (TempBuffer) and another to store completed KeyPairs (MainBuffer). When a user presses a key down, a new instance of KeyPair object 701 is created and the current key down, last key down, and timing data are stored (516) in it. This KeyPair is stored in the incomplete pair buffer. Positive values for the Flight feature may also be stored (516) at this point. When a user lets a key up, the incomplete pair buffer is scanned to see if it that key up completes a KeyPair. If it does, that KeyPair is stored (516) in the completed pairs buffer and removed from the incomplete pairs buffer. Negative Flight values may be stored (516) at this point. When the user finishes text input, a JSON file is created (517) with all the pairs' features which are extracted from the KeyPairs in the completed pair buffer. This JSON file is sent to the database 515.
Once a profile has been created, an anagram based authentication string is created (518) from the top 5%-10% of key pairs (by number of occurrence) or chosen from a list of phrases. The user is prompted to enter (518) the anagram. As before, keystroke data is captured at the user workstation and computationally-defined features for key pairs such as flight, dwell and downdown are computed (519) and communicated (520) for cloud- or server-resident classification (521) against distributions stored in database 515. In general, a rejected authentication brings the user back to the start of the loop (anagram entry 518) and may be repeated several times in case there was a false rejection. If the user is authenticated, then the additional keystroke data is added (522) to database 515. In some cases, situations or embodiments, the user's typed substantive responses in the context of a test, quiz or other coursework may be employed for authentication.
Turning more specifically to classifier operation of key sequence timing-type feature extraction and classification 353 (recall
A user creates a user profile and, as part of an enrollment phase 901 of audio feature extraction and classification 351, a web based application guides the user through the process of voicing (911) their name and/or a unique phrase multiple times into their computer's microphone. These utterances are sent (912) to cloud- or server-resident computations to have biometrically indicative, computationally-defined features extracted (913) and represented (914) in a JSON file and stored to database 915.
As part of certain coursework submissions 110 or in response to other non-coursework responses 311 (recall
In an illustrative embodiment of the voiceprint-type audio feature extraction and classification 353 (recall
The utterances are recorded as 22050 Hz 16 bit .ways, then run through an short-time Fourier transform (STFT) with an FFT size of 1024, a window length of 25 ms, and a step size of 10 ms. Twelve (12) MFCCs (and 1 extra features representing the total energy of the frame) and six (6) SSCs are extracted from each FFT frame. The MFCCs are generated with 26 filters, and the SSCs are generated with 6 filters/bands.
Turning more specifically to classifier operation of voiceprint-type audio feature extraction and classification 351 (recall
While the invention(s) is (are) described with reference to various embodiments, it will be understood that these embodiments are illustrative and that the scope of the invention(s) is not limited to them. Many variations, modifications, additions, and improvements are possible. For example, while certain feature extraction and classification techniques have been described in the context of illustrative biometrically indicative data and authentication scenarios, persons of ordinary skill in the art having benefit of the present disclosure will recognize that it is straightforward to modify the described techniques to accommodate other techniques features and classifiers, other biometrically indicative data and/or other authentication scenarios.
Embodiments in accordance with the present invention(s) may take the form of, and/or be provided as, a computer program product encoded in a machine-readable medium as instruction sequences and other functional constructs of software, which may in turn be executed in a computational system to perform methods described herein. In general, a machine readable medium can include tangible articles that encode information in a form (e.g., as applications, source or object code, functionally descriptive information, etc.) readable by a machine (e.g., a computer, server, virtualized compute platform or computational facilities of a mobile device or portable computing device, etc.) as well as non-transitory storage incident to transmission of the information. A machine-readable medium may include, but is not limited to, magnetic storage medium (e.g., disks and/or tape storage); optical storage medium (e.g., CD-ROM, DVD, etc.); magneto-optical storage medium; read only memory (ROM); random access memory (RAM); erasable programmable memory (e.g., EPROM and EEPROM); flash memory; or other types of medium suitable for storing electronic instructions, operation sequences, functionally descriptive information encodings, etc.
In general, plural instances may be provided for components, operations or structures described herein as a single instance. Boundaries between various components, operations and data stores are somewhat arbitrary, and particular operations are illustrated in the context of specific illustrative configurations. Other allocations of functionality are envisioned and may fall within the scope of the invention(s). In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the invention(s).
The present application claims benefit of U.S. Provisional Application No. 61/953,082, filed Mar. 14, 2014, the entirety of which is incorporated herein by reference.
Number | Date | Country | |
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61953082 | Mar 2014 | US |