Guidelines for 3800 Lab Reports

1) Lab reports on a particular statistical test should be written as if they were the Results section in a full empirical report. As such, they should not include any information that would be more appropriate in another section of a lab report. On some assignments, however, specific questions will be asked that go beyond what would normally appear in a Results section, and these should be incorporated into your report.

2) For ideas on how best to write about any particular analysis, take a look at a few recently published articles in an APA journal (e.g., Journal of Experimental Psychology: General). However, many authors do not write well, so you should probably look at Results sections in a few articles.

3) Pay close attention to spelling and grammar; these will be marked carefully and mistakes will be penalized heavily. Never hyphenate at the end of a line and do not use abbreviations except for statistical symbols. All reports must be typed (no hand-written corrections) in 12 point font and double-spaced. Use 1-inch (2.54 cm) margins all around. Every assignment is a maximum of 2 pages plus Figures and Tables. Unless otherwise specified, the APA guide is the definitive word on how a paper should be written.

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4) A good Results section is clear, concise, and easy to follow. For each assignment, there is a two-page maximum, but some of the assignments can be written in less than that. Please do not ramble solely to fill out the page limit. Also note that if you exceed two pages, the TA will only read the first 2 pages of your report. In a Results section, shorter and more concise is better, assuming that all of the necessary information is included. As an example of concise writing, the following is a sentence from a Results section that contains the means, the direction of the effect, and the t-statistic. ”Participants' satisfaction ratings were higher for shiraz (M = 7.2, SE = 0.2) than for merlot (M = 6.6, SE = 0.2), t(42) = 7.20, p < .0001." Note that a sentence such as "There was a significant main effect, F(1,22) = 5.21, p < .05." carries little information and is unacceptable.

5) See the APA guide concerning the proper number of decimal places. A series of numbers of the same type should all have the same number of digits following the decimal point.

6) There are differing opinions on how to report significance levels, but here is how it should be done for this course. If a result is nonsignificant, follow the statistic with ns. If the probability of a Type I error is less than .05, use whichever of the following is most accurate: p < .05, p < .01, p < .001, p < .0001. Always use ns or one of these 4 values.

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Guidelines for 3800 Lab Reports

7) The following is a list of how a number of statistical techniques and parameters should be written out in your reports. Most of these are universally accepted, but there are some local idiosyncrasies. Note that there is no excuse for getting these incorrect in your lab reports. Errors will be heavily penalized.

t-test F-test pooled variance estimate separate variance estimate Type I error Type II error analysis of variance (not ANOVA) one-way analysis of variance post-hoc test Tukey's HSD

completely randomized factorial analysis of variance interaction main effect simple main effect

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Guidelines for 3800 Lab Reports

repeated-measures analysis of variance split-plot analysis of variance Monte Carlo study power factor analysis eigenvalue orthogonal rotation varimax rotation

number of participants in a group: n = 21 mean: M = 14.3 standard error: SE = 1.2 Report mean and standard error, rather than mean and standard deviation. The mean and

standard error should include the measure, e.g., M = 214 ms. standard deviation: SD = 11.3 variance: s2 = 21.4 degrees of freedom: df = 4

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Guidelines for 3800 Lab Reports

t(19) = 3.56, p < .01

F(2,25) = 17.47, p < .001

Levene F(1,10) = 1.22, ns

q(2,19) = 1.35, ns

r =. 32, p < .05

r =.60, F(1,72) = 13.61, p < .001

r2 =.36, F(1,72) = 13.61, p < .001

R = .70, F(4,72) = 19.61, p < .0001

R2 = .49, F(4,72) = 19.61, p < .0001

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Guidelines for 3800 Lab Reports