Implement in-game lottery evaluation

[shippy]

#30 is useful, but it's more user-friendly to choose a choice at random and evaluate it on-screen. (This is requested by #70.)

[shippy]

Steps:

• Choose a block at random, then a trial from that block at random
  • This potentially favors blocks with fewer trials; a perfectly uniform probability could be achieved if all blocks are surveyed for number of trials and weighted correspondingly / if the random selection happened on the level of trials. Not a priority.
• Factor out code from the requisite XYZ_drawTask to draw the choice.
• Visualize participant choice (lottery vs. reference) -- simplest might be having the other disappear?
• Visualize true distribution of ambiguity
• Visualize the random number selection (animated line? displaying a hundred dots and highlighting one?)

Other items:

• Use a block that precedes the evaluation? Have an option?
• Save this in the DataObject? Where?

[shippy]

Closing. Future cosmetic improvements are tracked in #79.

[shippy]

Reopening, because Sarah is about to implement it better!

The initial implementation is conflating 2 things: the selection of block/trial to evaluate, and the evaluation itself. This limits the reusability of the lottery evaluation code. Decoupling it, and allowing users to call it from whatever context they want (post-block, task script, …) and thus with whatever abstraction they want, is going to make things much easier.

The general approach is as follows:

• The function showLotteryEvaluation receipts trial specification, block configuration, and anything else that is necessary to painting the lottery on the screen. (Maybe there's a Boolean switch that determines whether a new PsychToolbox Screen should be spawned?)
• Some function that will call showLotteryEvaluation for trials extracted by polling either all blocks, or all blocks that implement a certain condition, or one block at random, or anything else that might make sense for the task at hand. (To be clear, the function we will write should not be implementing all of these things at once. We will pick one thing at a time. The choice of which upstream function to call is up to the user.)

[skim725]

In showLotteryEvaluation we added an automatic timeout to line 63 (under Wait for keypress): previously, the program had been unresponsive to "5" after the display of "You have chosen the gamble" or "You have chosen the alternative to the gamble."

Now, the screen closes out after 5 seconds instead of being unresponsive forever.

[skim725]

IT WORKS

[skim725]

[Edit later]
SODM_pickTrials.m calls showLotteryEvaluation.m, and getOneBlockPerCondition.m.

Left to do: Display the fact that the Lottery Evaluations are about to start?

[shippy]

Formal things to do:

• place showLotteryEvaluation.m under lib/phases, getOneBlockPerCondition.m under lib/helpers or lib/phases/helpers, and SODM_pickTrials.m under tasks/SODM
• have @skim725 submit a pull request from a branch on her copy of this repository

[skim725]

Prof Levy had some suggestions:

[see changes in SODM_pickTrials.m]:

• She agreed that we need some sort of "intro" to the lottery fulfillments, or something to indicate that the trials are over.

• She said perhaps it would be better if participants had to press [5] in order to progress through each of the 4 lotteries? Otherwise it goes too fast for them (e.g. not enough time to process what "random draw got you a blue marble" means.)

• Shifting up text from bottom of screen - to make it easier to see?

[see showLotteryEvaluation.m]:

• Hedging the message to display in the case where lottery is chosen, based on if monetary or medical. "You chose the gamble. Random draw got you a [] marble" for monetary; "After experimental treatment, the outcome was: [medical outcome]" for medical.
  *This works now! Perhaps there is a way to make it more elegant.