To get a key to the lab:
- Go to Mary Claire’s office and request a key for rooms 359a, b, and c.
- After a few days go by physical plant (located on the back end of the fine arts building) to pick up your key.
- Your key should say AZP 45
To get access to the psychology computer lab (room 354):
- Go to Mary Claire’s office and request lab access.
- Once processed, your card will act as a key and you will have access to the lab from 8am until 10pm.
Important phone numbers:
- Phone numbers are kept on the dry erase board in room 359-a.
- 359-A: x8180
- Brooke’s office: x6196
- Brooke’s home: 228-1679
- Brooke’s cell: 216-7535
- Brooke’s UMN Office: (612) 624-7353
To access messages on the lab phone in 359-A:
- Enter 6666
- Enter RALI, or 7254
- First have the participants sign a consent form. These are generally half-sheets found in the gray cubbies in room A.
- Write the participants initials and participant number (sequential) under the column “Participants.” Mark the version of the experiment in which the participant will be run. This is usually done in a repeating diagonal pattern such that participant 1 is run in version 1 and 2 in version 2 etc. until you run out of versions and begin again with version 1. The clipboard is also the place to note whether the participant is a native English speaker. If the participant learned English by the age of 5, then he or she is considered a native speaker, so mark “yes.” Otherwise, mark “no” and note the age that he or she learned to speak English.
Running the Experiment
- Start the version of the experiment that you marked on the clipboard. Press the run button. Enter the participant’s number under “subject number” and the version number under “group.” Thus, participant 1 should be marked 1, 1. Then verbally give instructions to the participants (see Instruction sheet in the Lab Manual). While the participant is doing the experiment, fill out the rest of the information on the participation slip.
- When the participant has completed the experiment, give them their debriefing form and ask him or her if he or she had any issues with the experiment. Also answer any questions the participant may have.
- If the experiment involves money, pay the participants and get their signature (See lab manual under Paying Participants).
Instructions for Running Participants
First Time Runners:
- If this is your first time running participants, you need to shadow a member of the lab who has previously run participants. If you have previously run participants and are just trying to figure out what to do for this experiment, you are in the right place. The first thing to do is figure out what kind of an experiment it is that you are running. You can do this by either asking the lab supervisor or piloting the experiment yourself. I think that it is a good idea to pilot it because it gives you a familiarity with the program which allows you to solve problems if they arise. The experiments in this lab fall into one of several categories listed below. These are the instructions for each category.
Lexical Decision Task:
- All of the instructions will appear on the screen, but I will go over them briefly for you. You will begin by doing a practice of a lexical decision task. Your job is to answer whether the string of letters is a word in the English language or not by pressing “yes” or “no.” Try to answer as quickly as possible without losing accuracy. After the practice, you will be reading several stories. The stories will appear one line at a time in the center of the screen. At some point during the story, a “Get Ready” sign will appear followed by a string of letters. Once again your job is to determine whether the letters form a word or not. At the end of the story, there will be a comprehension question about the story. You will answer the comprehension question by pressing “yes” or “no.”
- Detailed instructions will appear for you on the screen. In short, you will begin by doing a practice of a lexical decision tasks. Your job is to answer whether the string of letters is a word in the English language or not by pressing “yes” or “no.” Try to answer as quickly as possible without losing accuracy. After the practice, you will read several stories. The stories will appear one line at a time in the center of the screen. At some point during the story, a “Get Ready” sign will appear followed by a string of letters. Once again your job is to determine whether the letters form a word or not. At the end of the story, there will be a comprehension question about the story. You will answer the comprehension question by pressing “yes” or “no.”
- Detailed instructions will appear for you on the screen. In short, you will be reading several stories. The stories will appear one line at a time in the center of the screen. Read at your own pace. To advance the story, press the “C” button. At the end of the story, there will be a comprehension question about the story. You will answer the comprehension question by pressing “yes” or “no.”
Story Completion (paper and pencil experiemnt):
- You will be reading and filling in several stories. First read the story that is given and then fill in the next two lines of the story in the way that you think is best. Repeat this for each story in the packet.
World fit (e.g. Modified Stroop/ Gernsbacher):
- You will be reading sentences one word at a time. After the sentence, a word will appear and you will want to press “yes” or “no” to answer whether the word fits with the meaning of the sentence. You want to try to do this as quickly and accurately as possible.
Stropp or Words and Colors:
- In this experiment, you will be reading sentences one word at a time. At the end of a sentence, a word will appear in a color. Your job is to say the color of the word and not the word itself. After a few sentences, you will be given a comprehension question. Answer the comprehension question by pressing “yes” or “no.”
- This is a more complicated experiment to run so the instructions for it will be listed in the following section with the instructions on scoring it.
- Direct the lab in what tasks need to be preformed and in what order.
- On lab-meeting day, make individual meetings with lab members during the week to help them with their tasks.
- Make sure all experiments are ready to go (consent, debriefing, sign-up sheets, and clipboard).
- Use Google Calendar to organize times to run experiments and schedule work hours for other lab members.
- Back-up electronic data files each week to lab network folder (or get someone to do this)
- Compile and sometimes analyze data.
Consent and Debriefing Forms:
- If the experiment has been run before, then check the top drawer of the file cabinet for leftover sheets. They should be labeled in folders. You might also want to check on the computer for examples of consent and debriefing forms.
- If it is a new experiment, model the consent and debriefing forms on previous experiments and check with Brooke for other information.
- All experiments need clipboards to keep track of participant numbers, which ones are native English speakers, and on which version the participants were run.
- There is a clipboard example for distant premise under experiment sheet templates in the lab manual folder on the desktop. This can be used as a template.
- There is also a blank clipboard template on the computer, but it is easier to use the pre-made clipboard.
- Participants sign up for studies online via Sona Systems.
- Experimenters should post all available time slots and will be notified when a participant agrees to come into the lab.
- Be sure to put the length of time that the experiment takes, as well as the location of the study, in the description of the study on Sona Systems.
- Pilot the experiment as lab supervisor so that you can help the other members of the lab figure out what the experiment is about and how to instruct participants.
- Be sure you or the lab member running the experiment has looked at the data output to make sure the computer is collecting the data as intended. This is important to avoid the “Matthew Mistake.”
- See also the instruction sheet for running experiments in the lab manual.
- Leave out consent/debriefing forms and the clipboard so that all experimenters can find them.
- Prepare a folder to put signed consent forms and pink participation sheets in.
After the Experiment
- Once the experiment is complete, compile the data.
- File consent and participation slips into a folder and place it in the file cabinet.
- In a separate folder, put clipboard sheets and any participant signatures for money (see also the note on running participants with money) and file in cabinet.
E-prime consists of a number of programs:
E-Studio is the programming interface which you will use to create the actual experiments. It is basically a drag and drop interface with a toolbox of items that you use to put the experiment together piece by piece. You may want to have e-studio open while you are looking through this so that you can get a better feel for what is being talked about.
Structure and Toolbox:
- The first step in any program is to build the structure of it. E-prime allows users to create a flow diagram of sorts representing how the experiment will progress. This diagram can be turned on or off by going to the “view” menu and selecting “structure”. This will present you with a hierarchy of objects that have been added to the experiment from the toolbox. It should be blank except for the experiment object and its session process, which are part of all experiments. You can add things to the session process by dragging them from the toolbox (also viewable from the “view” menu) and dropping them in the structure window. These objects can also be removed from the experiment by hitting the delete key while they are highlighted. Notice that deleted objects go into the part of the structure labeled Unreferenced E-objects; this simply means that they will not be part of the program when it runs, not that they are gone.
- Objects in the structure will be done in the order in which they are displayed. For instance, if you had 2 image displays and then an inline object, the images would be displayed in order (from top to bottom) followed by the inline code being executed.
- Image Display - The image display is used to display pictures on the screen for an amount of time specified in the properties menu of the image display object. To access the properties of any object simply double click the object once it has been added to the structure and a new window will appear; now click the icon in the top left corner and you will be presented with a wonderful bounty of options concerning the object in question.
- Inline - The inline is where actual code is written. If you don’t have programming background it is recommended that you familiarize yourself with the e-prime reference manual and users’ guide, which are located on top of the file cabinets. If you do have programming experience, you should find E-basic (the language used in e-prime) very simple. The control statements are very similar to those found in most modern programming languages and variable declaration and use are simple as well. There is not room here to cover the entirety of the language, but if you have particular questions about how to do something in e-basic go to the help menu then to “E-basic help;” then in the new window that appears, hit the “help topics” button in the upper left and type in the name of the function (or code word) of which you’re looking for a description.
- Sound Out - sound out is much like the image display, except that it plays a sound instead of showing an image
- Text display – same as image display except it is for text.
- Wait- causes the program to pause in its execution for a specified duration
- Label – a label allows the programmer to specify a point in a program to jump to. What this means is that if earlier in the program the programmer inserted an inline object that said “go to lable1,” then when the program reached that inline object it would jump immediately to the location of label1 and resume running from that location. This can be useful for running pilots of an experiment but remember to take it out when the actual experiment is run on subjects.
Lists and Procedures – a list is probably the most essential part of any e-prime experiment. A list is essentially an excel spreadsheet with some very special properties.
First of all, double click the list item once it is added to the structure. In each list there are three column headings that are built in: Weight, Nested, and Procedure. Generally the first two don’t need to be changed at all so don’t worry about them. The procedure column is used to indicate which of a “group” of objects the items you enter in a list will be interacting with this “group;” in e-prime is called a procedure.
You may remember that at the top of every experiment there is a “session procedure” this is simply saying that everything inside the session procedure will be executed as part of the experiment. To create a procedure that a row of items of a list will be used for simply type the name of the procedure into a cell of the procedure column. After you have done this, the procedure should appear in the structure as an indented item connected by a light gray line to the list from which it is working.
In order to actually add content to a list, such as text that you want presented by text displays inside the procedure you just created, you must add more columns to the list. To do this, double click on the list and in the window that appears click the “add attribute” button at the top. In this new column you may add information just as in a regular spreadsheet that can be accessed by objects in the “child process,” which is referred to by the process column entry for that row of the list.
A process is basically a timeline (like the process for the experiment itself) and contains objects that will be executed a number of times equal to the number of rows in the list from which a process was created. This means that the list/process combo is used to create a sort of loop. This works well because each time through the loop a different row of the list above is being referred to. What this means is that when you are in a child procedure you can use the name of an attribute column heading surrounded by brackets e.g. [attribute1] to refer to whatever is written in the cell in the column labeled “attribute1” for that time through the loop.