The development and analysis of tutorial dialogues in AutoTutor Lite

The goal of intelligent tutoring systems (ITS) that interact in natural language is to emulate the benefits that a well-trained human tutor provides to students, by interpreting student answers and appropriately responding in order to encourage elaboration. BRCA Gist is an ITS developed using AutoTutor Lite, a Web-based version of AutoTutor. Fuzzy-trace theory theoretically motivated the development of BRCA Gist, which engages people in tutorial dialogues to teach them about genetic breast cancer risk. We describe an empirical method to create tutorial dialogues and fine-tune the calibration of BRCA Gist’s semantic processing engine without a team of computer scientists. We created five interactive dialogues centered on pedagogic questions such as “What should someone do if she receives a positive result for genetic risk of breast cancer?” This method involved an iterative refinement process of repeated testing with different texts and successively making adjustments to the tutor’s expectations and settings in order to improve performance. The goal of this method was to enable BRCA Gist to interpret and respond to answers in a manner that best facilitated learning. We developed a method to analyze the efficacy of the tutor’s dialogues. We found that BRCA Gist’s assessment of participants’ answers was highly correlated with the quality of the answers found by trained human judges using a reliable rubric. The dialogue quality between users and BRCA Gist predicted performance on a breast cancer risk knowledge test completed after exposure to the tutor. The appropriateness of BRCA Gist’s feedback also predicted the quality of answers and breast cancer risk knowledge test scores.     

Human Timeline: A Spatial‐Kinesthetic Exercise in Biblical History

The Human Timeline invites students to physically re‐create biblical history. Each student holds a card that denotes an event randomly selected from the biblical timeline. They then arrange themselves chronologically to learn the correct flow of biblical history. Because of the movement involved and the arbitrary layout of the cards among their classmates, learners engage their spatial‐kinesthetic intelligences through this activity. The exercise proves popular among students who identify themselves as “visual” learners, and ultimately serves the biblical studies classroom by reinforcing biblical history as a necessary framework for understanding the biblical text.     

Even in correctable search, some types of rare targets are frequently missed

Socially important visual search tasks, such as airport baggage screening and tumor detection, place observers in situations where the targets are rare and the consequences of failed detection are substantial. Recent laboratory studies have demonstrated that low target prevalence yields substantially higher miss errors than do high-prevalence conditions, in which the same targets appear frequently (Wolfe, Horowitz, & Kenner, 2005; Wolfe et al., 2007). Under some circumstances, this \ldprevalence effect\rd can be eliminated simply by allowing observers to correct their last response (Fleck & Mitroff, 2007). However, in three experiments involving search of realistic X-ray luggage images, we found that the prevalence effect is eliminated neither by giving observers the choice to correct a previous response nor by requiring observers to confirm their responses. This prevalence effect, obtained when no trial-by-trial feedback was given, was smaller than the effect obtained when observers searched through the same stimuli but were given trial-by-trial feedback about accuracy. We suggest that low prevalence puts pressure on observers in any search task, and that the diverse symptoms of that pressure manifest themselves differently in different situations. In some relatively simple search tasks, misses may result from motor or response errors. In other, more complex tasks, shifts in decision criteria appear to be an important contributor.     

CHILD MALTREATMENT, BULLYING, GENDER-BASED HARASSMENT, AND ADOLESCENT DATING VIOLENCE: MAKING THE CONNECTIONS

Learning to relate to others begins at birth and carries forward to new relationships, which is why child maltreatment and exposure to intimate partner violence have emerged as powerful risk factors for future coercive and hostile relationship patterns. Although not inevitable, it is more likely that children who are victims of maltreatment will carry forward these behavior patterns into adolescence and adulthood, thus perpetuating bullying and harassment with peers and dating partners. We examine the importance of relationships in understanding how abusive patterns of relating to others are shaped throughout childhood and adolescence and how they can be prevented. While early relationships are very important, they are not deterministic; there are ample opportunities for corrective experiences to offset negative early experiences.     

What are the shapes of response time distributions in visual search?

Many visual search experiments measure response time (RT) as their primary dependent variable. Analyses typically focus on mean (or median) RT. However, given enough data, the RT distribution can be a rich source of information. For this paper, we collected about 500 trials per cell per observer for both target-present and target-absent displays in each of three classic search tasks: feature search, with the target defined by color; conjunction search, with the target defined by both color and orientation; and spatial configuration search for a 2 among distractor 5s. This large data set allows us to characterize the RT distributions in detail. We present the raw RT distributions and fit several psychologically motivated functions (ex-Gaussian, ex-Wald, Gamma, and Weibull) to the data. We analyze and interpret parameter trends from these four functions within the context of theories of visual search.     

Curvature is a basic feature for visual search tasks.

A curved target can be found efficiently among straight distractors in a visual search task. This could reflect the status of curvature as a basic feature for visual search. Alternatively, curvature could be detected as a locus of high variation in orientation. In a series of experiments it is shown that efficient search for curvature is possible even if local variation in orientation is eliminated as a cue. This suggests that curvature is part of the set of basic features for visual search and that this set is derived relatively late in the course of visual processing.     

Do intersections serve as basic features in visual search?

The status of 'intersection' as a basic feature in visual search tasks has been controversial. Under some circumstances, a target possessing this attribute (eg a plus) 'pops out' of a display of distractors that lack the attribute (eg Ls). However, those cases may be artifacts of other features such as relative size or number of line terminators. We report two sets of experiments with stimuli intended to control for these factors. Search for the presence or absence of intersections is very inefficient with these stimuli. The results suggest that intersection should not be included among the list of salient features that support efficient search through visual displays.