How do you specify how many options the user has to look through? For example, you are looking through multiple choices for each of the 50 states. How can you specify how long it takes the experienced user to scroll through and find the option they want (especially as some can be in the top of the list, middle, or end)? How can you add in the functionality that the user may know to type the first letter of the state and be brought to that list of states, therefore dramatically dropping scroll time?

I am curious to how to put that functionality in the models, so that i can accurately determine a time frame for inputing fields. An average time would suffice, but I dont know how to account for scrolling time at all. Or is that scrolling time already included in the widget?

You can always find out what time an operation takes by making a small CogTool storyboard, demonstrate the action you want to see, and then look at the visualization of the model. For example, if you want to see how long homing is, make a storyboard with a button and a keyboard, then demonstrate clicking on the button and then typing something on the right side of the keyboard. Computer the script then look at the visualization and you will see a red right-hand movement after the click and before the typing, which is the homing. Over over that homing box in the timeline and it will show yoiu the duration of the operator. Click on it, and yoiu can see the whole ACT-R trace that does that action.

Either way, in the frames you will probably want to use no rendering, with a background image for the widget itself, or a background image for the entire screen, because rendering a button or a link with CogTool skins will not get you the “tab” look you want.

For making predictions, this decision doesn’t change anything, because the choice of a widget type only impacts where Think operators are placed and buttons and links place Thinks the same way. you can read about this in the User Guide in Appendix C.