review of results

Review of ResultsReview of Results

From data analysis to From data analysis to presentationpresentation

APA manual (2001):APA manual (2001):

““The results section summarizes the data The results section summarizes the data collected and the statistical treatment of collected and the statistical treatment of them. First, briefly state the main results them. First, briefly state the main results of findings. Discussing the implications of findings. Discussing the implications of the results is not appropriate here. of the results is not appropriate here. Mention all relevant results, including Mention all relevant results, including those that run counter to the hypothesis. those that run counter to the hypothesis. Do not include individual raw scores or Do not include individual raw scores or raw data…” (p. 20).raw data…” (p. 20).

tt-test (two-groups)-test (two-groups)

Results (two groups)Results (two groups)A t-test for independent groups A t-test for independent groups

(female versus male) was conducted (female versus male) was conducted for the dependent measure escape for the dependent measure escape latency. The results revealed a latency. The results revealed a significant effect [significant effect [tt (38) = 2.24, (38) = 2.24, pp < .05]. As shown in Figure 1, Female < .05]. As shown in Figure 1, Female subjects escaped significantly faster subjects escaped significantly faster than male subjects.than male subjects.

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Insert Figure 1 about hereInsert Figure 1 about here__________________________________________

Results (two groups)Results (two groups)

A t-test for independent groups (female versus male) was conducted for the dependent measure escape latency. The results revealed a significant effect [t (38) = 2.24, p < .05]. As shown in Figure 1, Female subjects escaped significantly faster than male subjects.

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Figure 1. Absolute heading error (+/- SEM) on the probe test following latent learning test trials in room 500B. The female group had a significantly more accurate heading to the goal location than the male group.

One-way ANOVA (multiple One-way ANOVA (multiple groups)groups)

Tukey post-hoc testTukey post-hoc test

Results: Omnibus Results: Omnibus FF

Results: Tukey Post-hocResults: Tukey Post-hoc

Results (multiple groups)Results (multiple groups)A one-way analysis of variance (ANOVA) A one-way analysis of variance (ANOVA)

was conducted using the 4 levels of the was conducted using the 4 levels of the independent variable (control, 1 mg/kg, 4 independent variable (control, 1 mg/kg, 4 mg/kg and 8 mg/kg) and the dependent mg/kg and 8 mg/kg) and the dependent variable escape latency. The results variable escape latency. The results revealed a significant effect of the drug [revealed a significant effect of the drug [FF (3,36) = 6.96, (3,36) = 6.96, pp < .005]. < .005].

As shown in Figure 1, The control group As shown in Figure 1, The control group escaped faster than the 3 drug groups. escaped faster than the 3 drug groups. Tukey post-hoc analyses revealed that the Tukey post-hoc analyses revealed that the Control group differed significantly from all Control group differed significantly from all other other groups (other other groups (pps < .05).s < .05).

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Factorial designFactorial design

More than one IV (called factors)More than one IV (called factors) Advantages: Advantages:

One experiment instead of twoOne experiment instead of two Fewer subjects may be neededFewer subjects may be needed Can study interactions in addition to Can study interactions in addition to

main effectsmain effects

Simple Factorial DesignSimple Factorial Design

Two factorsTwo factors Two treatments (a.k.a., conditions or Two treatments (a.k.a., conditions or

levels) for each factorlevels) for each factor

Example (water maze):Example (water maze):

Sex x Cue condition (2 x 2)Sex x Cue condition (2 x 2)

Hypothesis: Females will perform better Hypothesis: Females will perform better than males when navigating in the than males when navigating in the presence of distal cues but not when presence of distal cues but not when navigating in the presence of proximal navigating in the presence of proximal cues.cues.


FemaleFemale

DistalDistalFemaleFemale

ProximalProximal

MaleMale

DistalDistalMaleMale

ProximalProximal

Sex

Sex FF

MM

Cue conditionCue conditionDistalDistal ProximalProximal


How many results?How many results? Two main effects (Sex and cue Two main effects (Sex and cue

condition)condition) Did males perform better than females?Did males perform better than females? Is distal better than proximal?Is distal better than proximal?

One interaction (Sex x cue condition)One interaction (Sex x cue condition) Does the effect of sex differ at different Does the effect of sex differ at different

levels of the cue condition?levels of the cue condition?

Columns from sham data Columns from sham data setset

Fem/DisFem/Dis

(A)(A)Fem/ProxFem/Prox

(B)(B)

M/DisM/Dis

(C)(C)M/ProxM/Prox

(D)(D)

Sex

Sex FF

MM

Cue conditionCue conditionDistalDistal ProximalProximal

This is not the data set you have

Cell and Marginal MeansCell and Marginal Means

16.816.8 25.325.3

25.725.7 24.824.8

Sex

Sex

FF

MM

Cue ConditionCue ConditionDistalDistal ProximalProximal

21.0521.05

25.2525.25

21.2521.25 25.0525.05Main effect of cueMain effect of cue

Main

eff

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f sex

Main

eff

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Marginal MeansMarginal Means


Coding IVs in SPSSCoding IVs in SPSS

Fem/DisFem/Dis

(1,1)(1,1)Fem/ProxFem/Prox

(1,2)(1,2)

M/DisM/Dis

(2,1)(2,1)M/ProxM/Prox

(2,2)(2,2)

Sex

Sex F (1)F (1)

M (2)M (2)

Cue conditionCue conditionDistal (1)Distal (1) Proximal (2)Proximal (2)

SPSS spreadsheetSPSS spreadsheet

Analyze: GLM Analyze: GLM Univariate Univariate

VariablesVariables

ResultsResults

Cell and Marginal MeansCell and Marginal Means

16.816.8 25.325.3

25.725.7 24.824.8

Sex

Sex

FF

MM

Cue ConditionCue ConditionDistalDistal ProximalProximal

21.0521.05

25.2525.25

21.2521.25 25.0525.05Main effect of cueMain effect of cue

Main

eff

ect o

f sex

Main

eff

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f sex



ResultsResults

Main effect of Sex, Main effect of Sex, FF (1,36) = 6.65, (1,36) = 6.65, pp < .05 < .05 Main effect of Cue, Main effect of Cue, FF (1,36) = 5.70, (1,36) = 5.70, pp < .05 < .05 Sex x Cue Interaction, F (1,36) = 8.53, p Sex x Cue Interaction, F (1,36) = 8.53, p

< .01< .01

Main EffectsMain Effects

Main effect of Sex

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Marginal Means Marginal Means Main effect of SexMain effect of Sex

Marginal Means Marginal Means Main effect of CueMain effect of Cue

Main effect of Cue

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Sex x Cue interactionSex x Cue interaction

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Results:Results:Main effectsMain effects Sex – not sigSex – not sig Cue – sigCue – sigInteractionInteraction Sex x Cue - Sex x Cue - sigsigHypothesis: Females will perform better than males when Hypothesis: Females will perform better than males when navigating in the presence of distal cues but not when navigating in the presence of distal cues but not when navigating in the presence of proximal cues.navigating in the presence of proximal cues.

ResultsResultsA 2 x 2 (Sex x Cue) factorial analysis of A 2 x 2 (Sex x Cue) factorial analysis of

variance (ANOVA) was conducted for the variance (ANOVA) was conducted for the dependent measure, escape latency. The results dependent measure, escape latency. The results showed a significant main effect of Sex [showed a significant main effect of Sex [FF (1,36) (1,36) = 6.65, = 6.65, pp < .05], a significant main effect of Cue < .05], a significant main effect of Cue [[FF (1,36) = 5.70, (1,36) = 5.70, pp < .05] and a significant Sex x < .05] and a significant Sex x Cue interaction [F (1,36) = 8.53, p < .01].Cue interaction [F (1,36) = 8.53, p < .01].

As shown in Figure 1, Female subjects As shown in Figure 1, Female subjects escaped significantly faster than male subjects in escaped significantly faster than male subjects in the distal cue condition. However, male and the distal cue condition. However, male and female subjects did not differ significantly in the female subjects did not differ significantly in the proximal cue condition. proximal cue condition.

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APA manual (2001):APA manual (2001):

““After presenting the results, you are After presenting the results, you are in a position to evaluate and in a position to evaluate and interpret their implications, interpret their implications, especially with respect to your especially with respect to your original hypotheses. You are free to original hypotheses. You are free to examine, interpret, and qualify the examine, interpret, and qualify the results as well as to draw inferences results as well as to draw inferences from them.” (p. 26)from them.” (p. 26)

APA manual (2001):APA manual (2001):““Simmilarities and differences between your Simmilarities and differences between your results and the work of others should clarify and results and the work of others should clarify and confirm your conclusions. Do not, however, confirm your conclusions. Do not, however, simply reformulate and repeat points already simply reformulate and repeat points already made; each new statement should contribute to made; each new statement should contribute to your position and to the reader’s understanding of your position and to the reader’s understanding of the problem. You may remark on certain the problem. You may remark on certain shortcomings of the study, but do not dwell on shortcomings of the study, but do not dwell on every flaw. Negative results should be accepted every flaw. Negative results should be accepted as such without an undue attempt to explain as such without an undue attempt to explain them away.” (p. 26)them away.” (p. 26)

review of results

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