I'm trying to program an experiment that includes multiple screens in a single "trial", e.g. an instruction screen, a picture, and rating screen. The instruction screen includes three different versions (NOW LATER STRATEGY) and then should present a randomly selected picture, and then proceed to a rating screen with a likert scale.

I'm having trouble with a few things:

1) I don't know where to change the location of picture files / where to upload them to.

2) I don't know how to randomize the instruction screen... is that in the block section? another [1-4=noreplace(instructions)]?

3) I don't know how to make the likert scale without making it an image. thoughts?

Thanks so much! See below...

B

****DEFINING EXPERIMENT****
<expt>
/blocks = [1=practice; 2=1]
</expt>

<data>
/columns =[date time subject blocknum trialnum trialcode response latency stimulus]
/format=tab
</data>

<defaults>
/fontstyle = ("Arial", 3.5%)
/screencolor = (0,0,0)
/txbgcolor = (0,0,0)
/txcolor = (255, 255, 255)
/minimumversion = "3.0.0.0"
</defaults>

**** INSTRUCTIONS *****
<instruct welcome>
/ txcolor = (255, 255, 255)
/ screencolor = (0, 0, 0)
/ nextkey = (" ")
/ prevkey = ("p")
/ nextlabel = "(Space) Next page"
/ prevlabel = "(p) Previous page"
</instruct>

<page welcome>
Welcome to this experiment.
</page>

<instruct block>
/ txcolor = (255, 255, 255)
/ screencolor = (0, 0, 0)
/ nextkey = (" ")
/ prevkey = ("p")
/ nextlabel = "(Space) Next page"
/ prevlabel = "(p) Previous page"
</instruct>

<page block>
Here are the instructions!
</page>

<instruct thankyou>
/ txcolor = (255, 255, 255)
/ screencolor = (0, 0, 0)
</instruct>

<page thankyou>
Thanks!!!!!
</page>


***** STIMULI ******

<item imagelist1>
/1 = "1.jpg"
/2 = "2.jpg"
/3 = "3.jpg"
/4 = "4.jpg"
</item>

<item imagelist2>
/1 = "5.jpg"
/2 = "6.jpg"
/3 = "7.jpg"
/4 = "8.jpg"
</item>

<item instructions>
/1 = "NOW"
/2 = "LATER"
/3 = "STRATEGY"
</item>

<item fixation>
/1 = "+"
</item>

*this will need to be set up as a likert scale or image
<item rating>
/1 = "1"
/2 = "2"
/3 = "3"
/4 = "4"
/5 = "5"
</item>

<text instructions>
/items= instructions
/select = replace
/position = (50,50)
/txcolor = (255,0,0)
</text>

<picture imagelist1>
/items = imagelist1
/position = (50,50)
/select = replace
/size = (300,300)
</picture>

<picture imagelist2>
/items = imagelist2
/select = replace
/position = (50,50)
/size = (300,300)
</picture>

<text fixation>
/items = fixation
/position = (50,50)
/txcolor = (255,0,0)
</text>


***defining trial

<trial ROCprac>
/stimulustimes = [1=fixation; 500=list.instructions; 3500=list.imagelist1; 9000=rating; 13000=fixation]
/validresponse = ("1","2","3","4","5")
/pretrialpause = 500
/timeout = 10000
</trial>

<trial ROC>
/stimulustimes = [1=fixation; 500=list.instructions; 3500=list.imagelist2; 9000=rating; 13000=fixation]
/validresponse = ("1","2","3","4","5")
/pretrialpause = 500
/timeout = 13500
</trial>

***defining block
<block practice>
/trials = [1-4=noreplace(imagelist1)]
/preinstructions = (welcome, practice_instructions)
/postinstructions = (thankyou, practice_instructions)
</block>

<block 1>
/trials = [1-4=noreplace(imagelist2)]
/preinstructions = (block, 1_instructions)
/postinstructions = (thankyou, 1_instructions)
</block>

All of this can be done via /stimulustimes in a single <likert> element.

In case of a web experiment, you upload them to the millisecond server in step 2 of the Web Script Wizard when registering your script.

Depends on what you want to do. Normally you simply use the given stimulus element's (here: <text>) /select attribute.

As already mentioned in response to Q1, see the documentation for the <likert> element.

I would also recommend you give the tutorials in the documentation another look as these cover the basic aspects your questions touch upon.

Does this mean that I would remove the <trial> element and replace it with the <likert> element? What if I only wanted the likert screen visible for the rating part (9000ms - 13000ms)? Would I use both then?

What I want to do is have three different words/instructions appear on the screen before an image. Both the instructions and images would be randomized. I figured out how to randomize the images; is it the same for text (e.g. "replace").

Thanks!

Yes. A <likert> is a special type of <trial>.

The <likert> allows you to control that via its /responsetime attribute (details in the docs).

No, that should not be necessary here.

Yes, the type of stimulus makes no difference as to how selection works.

Wonderful, thank you so much!

The program is now running (yay!!!) but I have a few other questions that I can't find answers to in the help/tutorial.

1. How do I get the rating text "Answer this question" and the scale to sync? They are one after another now.

<text rating>
/items = rating
/position = (50,50)
/txcolor = (255,0,0)
</text>

***defining trial
<likert ROCprac>
/ stimulustimes = [1=fixation; 500=instructions; 3500=imagelist1; 9000=rating; 13000=fixation]
/ pretrialpause = 500
/ timeout = 13500
/ anchors = [1="not at all"; 2="not much"; 3="neutral"; 4="some"; 5="a lot"]
/ position=(50, 90)
</likert>

2. How do I get an image to erase mid-trial? I can get it to disappear at the end, but not after it is presented.

Thanks again!

As already mentioned in my previous reply, you need to specify the desired /responsetime. Here:

/ responsetime = 9000

See the "How to erase stimuli" topic in the documentation.