Instructions for lab report

For this lab report, you will analyze the group data from the lab exercise, plot the group data means (provided by the instructor) on the graphs in the MEL Lab workbook, and write a lab report in APA format, emphasizing the method and results sections. The graphs from the workbook should be included with your lab report as figures.

From the Data Files link on the syllabus you will find two files for Lab 2.10, lab1_2_data.txt and lab1_2-tables.txt.

The file lab1_2-tables.txt contains the means for the four conditions (1=partial report, 0ms delay; 2=partial report, 150ms delay; 3=partial report, 500ms delay; 4=full report, 0ms delay). The first two tables are proportion correct in each condition overall (averaged across subjects. Use these means to create the figures (line graphs) in your workbook. You will include those graphs as figures in your lab report. The last two tables give the proportion correct for each subject in each condition

The file lab1_2_data.txt contains the data for analysis. Each participant’s data is on one row, and there are 9 columns. The first row contains variable names for each column. Column 1 is the subject number. The next 8 columns are the proportion correct for each subject in the 4 conditions, first the proportions correctly recalled in exactly the right order (ord1, ord2, ord3, ord4), then the proportions correctly recalled in any order (any1, any2, any3, any4).

You should therefore do two analyses for this lab report: One comparing the proportion correct in the 4 conditions for recall in exact order, and then the same analysis for recall in any order.

Steps for data analysis: (assuming you are using SPSS; you may use other analysis programs instead if you wish)

Import the data into SPSS

Save the data file to your hard drive by right-clicking the name of the file in the web browser and choosing “save as” on the pop-up menu.
Start SPSS
Open the data file in SPSS. You must select the file type of “text” and remember that the first line contains variable names.

Examine the data file for problems.

Look to see if there are missing data points, subjects who are at ceiling or floor (all correct or all incorrect), or subjects who have more than one line of data (either from repeating the experiment, or from two participants having the same number).
Look for outliers. Use the Explore option in the Analyze menu to create box plots and/or stem plots to identify outliers.
Decide what to do about outliers. Options include: eliminate that data point, eliminate that subject’s data, do nothing (keep the data as it is).

Use Analysis of Variance (ANOVA) to compare the 4 mean proportions correct in exactly the right order.

Is the main effect of condition significant? Does the pattern of differences confirm your hypothesis?
If there are particular pairs of conditions you need to compare to test your hypothesis, use paired-samples t-tests to make the comparisons.

Do the same analyses for the 4 mean proportions correct in any order.

Your lab report should be a manuscript in APA format, including all the necessary elements:

· Title Page

· Abstract

· Introduction

· Method

· Results

· Discussion

· References

· Tables and/or Figures

The Intro and Discussion can be very brief, and the references can be taken from the MEL LAB workbook’s discussion and/or the course readings list. The following will give you some pointers, and you should also consult your APA style guide.