Correlational & Differential Designs & APA Results Psychology 291 November 5, 2012

Correlational Design Research that seeks to measure the relationship between variables. Has multiple continuous variables. 2. How much fun do you expect to have tomorrow night? 3. How many alcoholic beverages do you plan on consuming tomorrow night? ( 1 alcoholic beverage = 12 ounces of Beer, 4 ounces of wine, 1.5 ounces of hard liquor) _________ No FunIndifferentLots of Fun

Differential Design Research that involves comparing two or more existing groups on some variable. Nominal and continuous variables. 1.Are you going to dress up in a costume for Halloween? Yes or No 2.How much fun do you expect to have tomorrow night? No FunIndifferentLots of Fun

APA Format Results

APA Rules to Keep in Mind Write in Past Tense First-level headings are centered and bold Remember to follow other APA rules (page layout, font, etc.), as well as consult the manual on-line Check APA format for Number formatting – All numbers zero through nine are written in word form unless they are followed by a unit of measure – All decimal numbers and numbers greater than 10 are written in Arabic numerals – Any number that begins a sentence must be in written form – Back to back numbers are written in word and number form: Twenty 20 inch monitors

Results Results section is “all about the data” – All data and results (even those that run counter to hypotheses) must be reported here Summarizes data collected and stats that were run Should begin with a description of the statistical test that was used May direct reader to Tables and/or Figures Do not interpret or discuss the results

Treatment of Raw Data How was the data for the dependent variable(s) arrived at? In order to run statistics a series of values must be turned into a single score for analysis – This may include tallying a P’s answers on a series of likert questions or reporting the P’s answer to an open-ended numeric question If you created a questionnaire that had reversed questions you must indicate which questions had to be reverse coded before analysis could begin

Types of Results Descriptive Statistics – Means, Standard Deviations, Ranges… – Tables & Figures Inferential Statistics – Results of Statistical Analysis – e.g. ANOVA, t Test, Correlation, Chi Square …

Reporting Central Tendency & Dispersion Measures of Central Tendency and Dispersion (e.g. means and standard deviations) are often given in the Results section If you are reporting a mean, it should always be accompanied by a measure of dispersion Often presented in Tables to simplify presentation and when there are too many values to reasonably relay (See Table 1) Example in text: – The mean score for men on the verbal test was 23.6, with a standard deviation of Example following text: – Women had a slightly higher score than men on the verbal test (M = 23.61, SD = 2.10 for men, M = 26.94, SD = 1.98 for women).

Inferential Statistics The type of statistical test that you will choose depends on: – The type of data collected Nominal, ordinal, interval, ratio – The type of research design Experimental Differential (quasi-experimental) Correlational

Reporting Inferential Statistics t (81) = 2.598, p < The letter of the test (t, F, r, etc. and p) and M and SD all need to be italicized but not the numbers or symbols (=, <, etc.) Statistics must be part of a sentence Type of Test Degrees of Freedom Obtained Valued P value tells you if the test is significant or not

What is this “p” value thing? Every decision we make as the potential to be the wrong one (i.e. due to chance rather than our manipulation) The p value is our “acceptable risk” If we set α =.05 we accept a 1 in 20 chance of making the wrong decision, therefore: If the p value is less than (<) 0.05 the test is significant If the p value is more than (>) 0.05 the test is not significant

Experimental Design A One-Way ANOVA was performed and significant differences were found between at least two groups, F(2,44) = 3.835, p <.030. Tukey’s post hoc test revealed that participants in the Alcoholic Beverage Condition (M= 63.75, SD= 7.19) and the Non-Alcoholic Beverage Condition (M= 53.13, SD= 7.93) had significantly longer reaction times (in ms) than participants in the Water condition (M= 39.33, SD= 16.68). ANOVA ReactionTime Sum of SquaresdfMean SquareFSig. Between Groups Within Groups Total

Differential Design Independent Samples Test Levene's Test for Equality of Variancest-test for Equality of Means FSig.tdfSig. (2-tailed) Mean Difference Std. Error Difference 95% Confidence Interval of the Difference LowerUpper AmountFunEqual variances assumed Equal variances not assumed An Independent Samples t-test was performed and participants who wore a Halloween costume (M= 5.68, SD= 1.18) anticipated having significantly more fun than participants who reported not wearing a Halloween costume (M= 3.60, SD= 1.43), t(45) = , p <.001.

Correlational Design Correlations AmountFunNumBeverages AmountFunPearson Correlation1.591 ** Sig. (2-tailed).000 N47 NumBeveragesPearson Correlation.591 ** 1 Sig. (2-tailed).000 N47 **. Correlation is significant at the 0.01 level (2-tailed). A Pearson correlation revealed a significant positive correlation between the amount of fun anticipated and number of alcoholic beverages consumed by participants, r(45) =.591, p <.001. As number of alcoholic beverages consumed increased, so did the amount of fun anticipated and vice versa.

Tables and Figures Tables and Figures may be used to clarify data being presented in a Results section however they should never appear in the body of your text – Tables are often used to report means and standard deviations – Figures are used to represent interactions between variables and emphasize differences between groups Direct readers by adding (Table 1) or (Figure 1) at the end of sentences in your Results section They should not repeat information presented in the Results section

Tables Tables are used to present data when it would be unmanageable to present them in the results section (i.e. too many M & SD) Are presented in the a sans serif font (e.g. Arial) size 12 Contain no vertical lines Contain minimal horizontal lines Begin with a Table number and description Follow after References and Appendices

SAMPLE APA PAPER 13 Table 1 Mean response time of participants (ms) after consuming different beverages. ConditionM (SD) Alcoholic Beverage63.75 (7.19) Non-alcoholic Beverage53.13 (7.93) Water39.33 (16.68)

Figures Greyscale (no colours) Label Axes but do not include a title Legends (if applicable) must fall within the axis lines Figure presented in a sans serif font (e.g. Arial) between size Figure Caption presented in serif font (same as body of text) size 12 – Goes below the figure and describes the what is being shown No gridlines or borders (the only lines will be the axes) Follow after References, Appendices, and Tables Figure should fill the width of the page If presenting means, SD or SEM should be included as error bars

SAMPLE APA PAPER 14 Figure 1. A comparison of the amount of fun anticipated by participants either wearing or not wearing a costume on Halloween. (Error bars represent +/- SEM)

In Class Exercise Using the attached document, complete an APA format Results section.attached document You may type up your document and print it or it to if you wish for it to be