Speier, Vessey, Valacich 2003 - the effects of interruptions, as complexity, and information presentation on computer supported decision-making performance
–"the interruptions facilitate performance an simple tasks, while inhibiting performance on more complex tasks"
–" special presentation formats were able to mitigate the effects of interruption while symbolic formats were not"
-interruptions have been defined as uncontrollable unpredictable stressors that produce information overload, requiring additional decision-makers effort they require immediate attention and insist on action.
–The difference between distractions and interruptions. Distractions are detected by different sensory channel from the one used for primary primary task and maybe ignored, interactions however use the same sensory trial for both the interruption and the primary task, does decision maker cannot choose to ignore interaction clues. This might need to laws of memory contents and confusion, negatively influencing performance
–distraction conflict theory suggests that distractions facilitate performance on simple tasks and inhibit performance on complex tasks. The narrowing of attention likely results in a decision maker processing fewer information cues, some of which may be relevance to completing tasks successfully
- interruptions and presentation format: a match or cognitive fit occurs when the information emphasised in the particular presentation format (symbolic or spatial) matches that required to most easily complete the task. Symbolic format (tables) are good for presenting discrete set of symbols while spatial format (graphs) is better for depicting relationships among discrete sets of symbols
Schmitz, Heinz, Metrailler,Opwis 2009: cognitive load in e-commerce applications–measurement and effects of user satisfaction
–guidelines for designing usable interfaces recommend reducing short-term memory load. NASA TLX and secondary task (visual monitoring) were used to assess usage of four online bookstores. Users were not allowed to use search, but only to browse the menus. At the end users were asked how much would they prefer search feature then just browsing. While there was no significance on secondary task the high correlation between NASA test and browse/search preference suggests that browse/search preference could be used as a heuristic for assessing how good the browsing environment is.
–Well-designed websites take up more of the cognitive resources for an experienced users, it can be explained by users being able to focus more.
–It's easily lead in this study the secondary task was too difficult and badly placed on the screen
Todd, Benbasat 1994 : the influence of decision aids on choice strategies under conditions of high cognitive load
–According to cost benefit framework the joint objectives of decision-makers are to maximise accuracy and to minimise effort. Often referred may be weighted more heavily than accuracy because feedback in an effort is relatively immediate.
–In many studies effort reduction was far more important than accuracy maximisation, but this might be because effort is the only salient variable. In settings where the decision maker must live with the consequences of the decisions it may be that the decision quality becomes the primary concern.
Hong THing Tam 2003: designing product listing pages on e-commerce websites: and examination of presentation mode and information format
–unclear paper but the really interesting methodology. A mockup website for shopping for groceries contained products of 20 made up brands. In one condition products were shown with the picture in another condition they were shown without a picture. Every time the brand name was shown exactly the same way, and the participants were tested on how well the remembered brand names. It was found that brand names in the pictured condition were remembered better.
Nicholson et all 2005: using distraction conflicts theory to measure the effect of distractions an individual task performance in a wireless mobile environment
- A group of students was given laptops and asked to perform Excel tasks of different difficulty while being in the same room in the cafeteria setting. From the projector different distractions were shown on the wall in front of students eyes: high distraction was a video of a group of students talking about holiday, low distraction was a news TV, no distraction was nothing.
- It was found that performance decreased only enter high distraction condition and only for the high difficulty task.
- It is suggested that mobile wireless work [laptops] is more suitable for simple or well-trained tasks, while more complex tasks should be performed in a more controlled setting, such as an office.
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