Touch screen technology is rapidly increasing, and at the same time there is a shifting, aging population. As the percentage of the population over the age of 65 increases, adults of the age group are adopting smartphones and tablets more now than ever before. Although older adults are adopting touch screen devices, they face many challenges when interacting with said devices, such as not knowing how to navigate between pages, not knowing where to click for an action to occur, and the touch screen interface is often too sensitive or the buttons are not big enough. Furthermore, the challenges of aging, specifically sensory and cognitive decline resulting from aging affect comprehension and spacial processing, which are critical when navigating through an interface. The purpose of this thesis was to better understand redundancy effect applied to females and males between the ages of 65 and 84. There were two tasks of different lengths, and for each task there were two designs. The first design included text only buttons, and the second included symbol + text buttons, the latter being the redundant interface. Quantitative results yielded no significant results for time for either task. Qualitative results included ratings for ease of navigation, general satisfaction, overall understanding, and button design preference. Preferences between text only buttons were statistically significant; for the task of online grocery shopping and booking a cruise, females prefer text only buttons and males prefer symbol + text buttons (p = 0.0068 and p = 0.0024). Although button design had no significance in completing a task, significant preference results indicate likelihood to return to a given website. Furthermore, although quantitative results were not significant, gender did influence average times per task and average ratings across categories. Further research could be conducted with larger sample sizes, other forms of redundancy, and larger tasks, however it is evident through this experiment that gender has an impact on how adults between 65 and 84 perceive and navigate through touch screen interfaces given the constraints of the symbols used, ages, and task designs. Therefore, concluding recommendations based on the qualitative data suggest that designers should create gender specific interfaces based on gender favored websites, or design based on the ability to customize the interface upon entering a website.

Research in the area of multimedia instruction has yielded results that indicate that learning is better when verbal information is presented auditorily instead of visually (i.e. modality effect) and when redundant on-screen text is removed from the instructional environment (i.e. redundancy effect). The present study aimed to extend these findings by exploring the effects of presentation modality and redundancy of verbal information on students' ability to apply and recall a historical inquiry strategy. Fifty-six students were randomly assigned to three treatment groups, which differed according to the presentation mode combination used to present the strategy instruction. Specifically, students received the instruction either as animation and narration, animation and text, or animation, narration, and text. The students were engaged in a multimedia strategy intervention for a total of five days, for approximately 25 minutes a day. Three strategy application tests (i.e., pre-test, post-test, maintenance test) and a recall test were used to measure the students' learning. Data attained through the strategy application tests and recall tests were analyzed using Analysis of Variance (ANOVA) procedures. The results of the study revealed significant differences in the training main effects analysis indicating that strategy instruction can be effectively provided in a multimedia learning environment. However, no significant differences were found for the modality and redundancy main effects indicating that there was no difference in strategy application or recall between the groups. Although the results did not provide the statistical significance that supports the literature on the modality and redundancy effects, the implications of the findings of the research provide several viable areas for future research. / Ph. D.

Using an allergist task, Uengoer, Lotz and Pearce (2013) found that in a design A+/AX+/BY+/CY-, the blocked cue X was indicated to cause the outcome to a greater extent than the uncorrelated cue Y. This finding has been termed “the redundancy effect” by Pearce and Jones (2015). According to Vogel and Wagner (2017), the redundancy effect “presents a serious challenge for those theories of conditioning that compute learning through a global error-term” (p. 119). One such theory is the Rescorla-Wagner (1972) model, which predicts the opposite result, that Y will have a stronger association with the outcome than X. This thesis explored the basis of the redundancy effect in human causal learning. Evidence from Chapter 2 suggested that the redundancy effect was unlikely to have been due to differences in attention between X and Y. Chapter 3 explored whether differences in participants’ certainty about the causal status of X and of Y contributed to the redundancy effect. Manipulations aimed at disambiguating the effects that X had on the outcome, including outcome-additivity training and low outcome rate, resulted in lower ratings for this cue and a smaller redundancy effect. However, the redundancy effect was still significant with both manipulations, suggesting that while participants’ uncertainty about the causal status of X contributed to it, there may have been other factors. Chapter 4 investigated whether another factor was a lack of inhibition for cue C. In a scenario where inhibition was more plausible than in an allergist task, a negative correlation between causal ratings for C and for Y, and a positive correlation between ratings for C and the magnitude of the redundancy effect, were found. In addition, establishing C as inhibitory resulted in a smaller redundancy effect than establishing C as neutral. Overall, findings of this thesis suggest that the redundancy effect in human causal learning is the result of participants’ uncertainty about the causal status of X, and a lack of inhibition for C. Further work is recommended to explore whether combining manipulations targeting X and Y would reverse the redundancy effect, whether effects of outcome additivity and outcome rate on X are the result of participants’ uncertainty about this cue, and the extent to which participants rely on single versus summed error.