Unbounded Human Learning: Optimal Scheduling for Spaced Repetition

In the study of human learning, there is broad evidence that our ability to retain information improves with repeated exposure and decays with delay since last exposure. This plays a crucial role in the design of educational software, leading to a trade-off between teaching new material and reviewing what has already been taught. A common way to balance this trade-off is spaced repetition, which uses periodic review of content to improve long-term retention. Though spaced repetition is widely used in practice, e.g., in electronic flashcard software, there is little formal understanding of the design of these systems. Our paper addresses this gap in three ways. First, we mine log data from spaced repetition software to establish the functional dependence of retention on reinforcement and delay. Second, we use this memory model to develop a stochastic model for spaced repetition systems. We propose a queueing network model of the Leitner system for reviewing flashcards, along with a heuristic approximation that admits a tractable optimization problem for review scheduling. Finally, we empirically evaluate our queueing model through a Mechanical Turk experiment, verifying a key qualitative prediction of our model: the existence of a sharp phase transition in learning outcomes upon increasing the rate of new item introductions.Comment: Accepted to the ACM SIGKDD Conference on Knowledge Discovery and Data Mining 201

Benchmarking Treatment Response in Tourette’s Disorder: A Psychometric Evaluation and Signal Detection Analysis of the Parent Tic Questionnaire

This study assessed the psychometric properties of a parent-reported tic severity measure, the Parent Tic Questionnaire (PTQ), and used the scale to establish guidelines for delineating clinically significant tic treatment response. Participants were 126 children ages 9 to 17 who participated in a randomized controlled trial of Comprehensive Behavioral Intervention for Tics (CBIT). Tic severity was assessed using the Yale Global Tic Severity Scale (YGTSS), Hopkins Motor/Vocal Tic Scale (HMVTS) and PTQ; positive treatment response was defined by a score of 1 (very much improved) or 2 (much improved) on the Clinical Global Impressions – Improvement (CGI-I) scale. Cronbach’s alpha and intraclass correlations (ICC) assessed internal consistency and test-retest reliability, with correlations evaluating validity. Receiver- and Quality-Receiver Operating Characteristic analyses assessed the efficiency of percent and raw-reduction cutoffs associated with positive treatment response. The PTQ demonstrated good internal consistency (α = 0.80 to 0.86), excellent test-retest reliability (ICC = .84 to .89), good convergent validity with the YGTSS and HM/VTS, and good discriminant validity from hyperactive, obsessive-compulsive, and externalizing (i.e., aggression and rule-breaking) symptoms. A 55% reduction and 10-point decrease in PTQ Total score were optimal for defining positive treatment response. Findings help standardize tic assessment and provide clinicians with greater clarity in determining clinically meaningful tic symptom change during treatment

Simulating Ability: Representing Skills in Games

Throughout the history of games, representing the abilities of the various agents acting on behalf of the players has been a central concern. With increasingly sophisticated games emerging, these simulations have become more realistic, but the underlying mechanisms are still, to a large extent, of an ad hoc nature. This paper proposes using a logistic model from psychometrics as a unified mechanism for task resolution in simulation-oriented games

Cultural Basis of Sport Anglersˈ Response to Reduced Lake Trout Catch Limits

The cultural domain of southeastern Wisconsin anglers along Lake Michigan was assessed from responses to a state‐proposed reduction in the daily allowable catch of lake trout Salvelinus namaycush. The studyˈs baseline was an extensive random survey in 1980 of the areaˈs anglers with respect to Lake Michigan fishery resources. The 1984 lake trout issue was addressed by a restudy involving a small dimensional subsample of 1980 respondents and was cross‐validated with ethnographic interviews. The findings suggest that anglers have responded over time to the stateˈs policy proposals in a manner consistent with a stable value system that is not seriously masked by changes in short‐term attitudes about the fishery. The results further indicate that, once a good cultural data base is established, the sociocultural impacts of proposed fishery policies can be evaluated inexpensively by a restudy approach.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141485/1/tafs0503.pd

Familie-Stamrulle vedkommende Eliesonske, Ankerske, Colletske, Kiønigske m. m. m. Familier fra Slutningen av 1600 til 1874 o. s. v.

"Særtryk af Personal historisk tidsskrift VII. R. 2. Bd. 3. H."Mode of access: Internet.Cataloging supported by the Schoenleber Foundation, 2000