All Questions
254 questions
30
votes
3
answers
78k
views
Choice between Type-I, Type-II, or Type-III ANOVA [duplicate]
We have a dataset with three variables (dV: self-reported measure on scale 1-5, assumed to be metric; iV1: factor with 4 levels; iV2: factor with 8 levels). We are interested whether the dV differs in ...
- 677
1
vote
1
answer
435
views
Two-way ANOVA, what to do next?
I used a 3x2 between-subject ANOVA to examine the effect of colour (three levels: colourless, light red, and dark red) and odour (odourless or not) on perceived sweetness. The results indicated ...
- 21
0
votes
1
answer
18k
views
What does it mean to have negative values for both lower and upper bounds on a 95% Confidence Interval on ANOVA?
My data shows 95% CI = [-1.07, -0.40], what does the negative sign indicate and how do I interpret the data? as I think it is significant for not capturing the value of 0.
- 9
1
vote
1
answer
5k
views
ANOVA result indicated that there were sig. differences while Tukey post-hoc test revealed that there were no statistically sig. differences [duplicate]
I was conducted one-way ANOVA analysis to examone the level of knowledge shaorng among the employees based on there age differences. One-way ANOVA indicated that there were significant differences in ...
3
votes
2
answers
8k
views
Help with Anova of categorical and continuous variable in R and SPSS output
I am having some trouble running an Anova on categorical variables in R and matching SPSS output. What I need to do is run an anova on the dataset below (its a made up data set). But, I need to know ...
4
votes
2
answers
11k
views
Post-hoc for 2x2 mixed design ANOVA using SPSS
I am analysing an experiment run with 20 participants using a $2\times 2$ mixed design ANOVA. The experiment has
one within subjects variable A with two levels (a1, a2)
one between subjects variable ...
- 143
3
votes
1
answer
627
views
How can I perform post-hoc tests to the ANOVA performed during K means clustering?
If I have highly dimensional data and perform k means clustering, I can end up with clusters that differ more on some axes than others.
SPSS provides the option to return an ANOVA for each variable, ...
- 2,171
4
votes
2
answers
548
views
R p-value half to SPSS rANOVA
I have done rANOVA in SPSS and then in R and got two different p-values from the same model. While SPSS gives 0.032, R gives 0.0162, which when rounded is a half. Other data are exactly the same.
1. ...
- 251
5
votes
1
answer
4k
views
Why is ANOVA interaction no longer significant after including a covariate?
I have initially run a 2x2x2 Anova and found some significant interaction between the independent variables. I then ran a ANCOVA where I added a covariate. I am confused with how to interpret the ...
- 51
0
votes
1
answer
130
views
Repeated measures
I have administered an instrument (4 subscales, total items 32, no. of items in each subscale 12, 7, 9 & 4) three times over an year. I have worked out the factor scores. I am not sure if I should ...
3
votes
2
answers
10k
views
Repeated measures ANOVA: Mauchly's test undefined
I'm doing a two-way between-within ANOVA in SPSS. I have two groups with 9 subjects each (so total = 18), and 24 levels of one repeated measure.
I understand why Mauchly's test of Sphericity has no ...
- 81
1
vote
0
answers
437
views
What statistical methods to use for analysis of a scenario questionnaire?
I've produced a questionnaire with 3 parts, demographics, attitude questions, and then a final section on particular scenarios. I'm looking to analysis people's response to the scenarios - as in what ...
- 11
1
vote
2
answers
1k
views
How to analyse three way ANOVA that also has pre-post and one within subjects factor?
I'm currently having a problem understanding on how to enter and calculate my data in SPSS.
I have a three way design in which there are 2 variables each in
Experts vs Novice;
Guided Discovery vs ...
- 11
0
votes
1
answer
457
views
Two-way ANOVA repeated measures
I would like to know, if you got a significant interaction in a two-way repeated measures ANOVA in SPSS, how can you visualize the interaction (especially using syntax)?
4
votes
1
answer
1k
views
Checking normality of residuals in 2x2 mixed methods ANOVA
I am running a 2x2 mixed method ANOVA (with one between-group factor and one within-group factor - time 1 and time 2). I want to check whether the assumption of normality of residuals is met. When I ...
- 41
5
votes
1
answer
7k
views
Variances not homogeneous problem in ANOVA mixed between-within subjects, too bad?
I'm conducting a 2x3 mixed between-within subjects ANOVA (group x time). I have 20 participants, 10 for each group, who undergo all the 3 measures over time.
Levene's test of equality of variances is ...
- 173
0
votes
1
answer
4k
views
Normality test for anova mixed model in SPSS: I did it in two ways but the results are contrasting
I'm conducting an ANOVA mixed model 2 X 3 (group X condition). Right now, I'm checking for the assumptions of ANOVA, such as normality. I should check indipendently for group and condition, right? I ...
- 173
9
votes
3
answers
29k
views
Post hoc test in a 2x3 mixed design ANOVA using SPSS?
I have two groups of 10 participants who were assessed three times during an experiment. To test for differences between groups and across the three assessments, I ran a 2x3 mixed design ANOVA with <...
- 173
11
votes
5
answers
29k
views
Calculating eta squared from F and df
I'm trying to compute ANOVA effect sizes from papers that provide an F value without other information. If I understand correctly, the effect size for a single-factor ANOVA is
$$
\eta {2} = \frac{ss_{...
- 634
2
votes
2
answers
15k
views
How to do repeated measures ANOVA for two groups in SPSS and 12 time points?
I am measuring one parameter (say weight) repeatedly at different time points (say monthly, for 1 year) for two groups (say experimental and control groups). My data looks something like data posted ...
- 340
2
votes
0
answers
93
views
ANOVA variable that is both BETWEEN & WITHIN
Does anyone know how / if can you treat an independent variable as BOTH a between AND within subjects variable (ideally in SPSS ANOVA-repeated measures). That is, we have a repeated measures study ...
- 21
10
votes
1
answer
6k
views
Justification for low/high or tertiary splits in ANOVA
I have two groups of participants and they all took the same measurements.
When I perform a median split on one of the measurements to test my hypothesis about an interaction, the dependent ...
- 315
2
votes
1
answer
660
views
When are tertiary splits un/justified?
I'm studying neuroscience and have a question about presenting some data. I would like to know if tertiary splits are acceptable when the variable in question is normally or not normally distributed. ...
- 315
4
votes
1
answer
5k
views
Testing anova hypothesis with contrasts in R and SPSS
Using data and answers from this question I was trying to test the hypothesis $H_0:-3\mu_1-\mu_2+\mu_3+3\mu_4=0$
...
- 561
0
votes
1
answer
4k
views
What does it mean to have an F-value of .000 and Sig. of 1.000 (in SPSS)?
We conducted this very simple 2x2 Between Subjects Factorial Design Experiment, where the DV were their answers to a classic insight problem. Since there is only one correct answer to the problem, the ...
- 3
-1
votes
1
answer
239
views
How can I change the scores to make interaction effect in two way ANOVA significant?
My question is how to make an interaction effect become significant in two-way ANOVA.
If my main effect A has an F value of F(1,80)=25.5 for example, and my main effect B has an F value of F(3,80)=15,...
- 1
2
votes
1
answer
4k
views
Mixed linear model with repeated measures in SPSS
I'm trying to run a mixed linear model analysis with SPSS. When I try to run the analysis, SPSS gives the following error message: ...
- 21
3
votes
0
answers
871
views
Split-split-split plot cross-over design... is this even possible?
I'm doing statistical analysis on a psychology study I ran a short while ago, and I'm starting to think that I've designed myself into a corner.
In the study, we measured participants' pointing ...
- 43
2
votes
1
answer
10k
views
How to interpret an interaction effect in SPSS output for a repeated measures anova with between and within group factors?
I have conducted a repeated measures ANOVA, with 2 factors:
One between factor (Ex_control: exercise intervention versus control)
One within factor (...
2
votes
0
answers
2k
views
What is the difference between univariate post-hoc tests after MANOVA and usual ANOVAs?
When I run a $2 \times 4 \times 5 \times 6$ (Sex $\times$ AgeGroup $\times$ HighestDegree $\times$ Ethnicity) MANOVA (with 20 dependent variables) in SPSS, it presents tests of between subjects ...
- 21
1
vote
3
answers
2k
views
How should I analyze data with repeated measures variables and integer between-subject factors?
I ran a study, where a single variable was measured repeatedly for each participant, under different conditions. Analyzing this data with SPSS has been rather straightforward, by using the General ...
- 43
0
votes
1
answer
739
views
How can partial eta squared be 5% and yet SPSS says 0.045?
The partial eta squared indicates that gender explains 5% of the variance in drugs and ethnicity explains 6% of the variance in drugs. These are small effect sizes.
I am not sure I understand this ...
3
votes
2
answers
276
views
How to determine if a change in F value when introducing a covariate, is significant?
My question may be very basic but I hope that you can help me.
I have got two groups (A and B). I am measuring two continuous biological measures (X and Y) which are significantly positively ...
- 31
2
votes
1
answer
4k
views
How to analyse multiple between subjects factors in a mixed ANOVA in SPSS?
I am performing a Mixed between subjects Anova where I have multiple time points that subjects have completed a measure at.
The within subjects factor is time.
The between subjects factors include ...
- 21
4
votes
3
answers
14k
views
Repeated measures ANOVA or Friedman test?
I have a study with 35 subjects who received hypercoagulability testing at 4 different times (before surgery, after, at 1 week, and at 1 month). Each subject has 9 different test of hyper ...
- 41
2
votes
1
answer
2k
views
How to do a repeated measures ANOVA with missing combinations in spss
I currently have a setup, for which I want do do an ANOVA in spss. In my model I need to include four factors (I'll call them factor1 to ...
- 2,671
1
vote
3
answers
12k
views
Where are the t-values in my pairwise comparisons?
I have data from a study with three conditions. The independent variable was within-subjects and within-items.
I did an F1 and F2 analysis (= twice a repeated measures ANOVA) on the averages, by ...
- 739
9
votes
2
answers
13k
views
How to test for normality in a 2x2 ANOVA?
Study Design: I showed participants some information about sea-level rise, focusing the information in different ways, both in terms of the time-scale and the magnitude of potential rise. Thus I had a ...
- 447
1
vote
0
answers
620
views
Aligned rank transform on time series data
I have some time-series data that I wish to test to see if a certain factor has an effect. There are few samples per time step (10 on average), but the whole time-series has 306 samples. When divided ...
- 221
1
vote
1
answer
8k
views
Justification of aggregation in multi-level model - ICC in SPSS
I am running a multi-level model on data which is set out with one row per individual survey return, each with Individual ID and Organisational ID as columns. There are variables which can be ...
3
votes
3
answers
17k
views
How to assess differences between three groups in a pretest - posttest design using SPSS?
I have a dataset that includes one independent variable with 3 levels (group 1, group 2, and group 3) and a repeated dependant variable (pre test score, post test score).
I am using the statistics ...
- 31
2
votes
1
answer
28k
views
Estimated Marginal Means or means from descriptives?
I'm currently looking at a 2x2 Repeated Measure Anova for an undergrad project but I'm struggling to find information about which means to report.
I will be reporting the Within-Subjects Anova,the ...
- 21
2
votes
1
answer
1k
views
How to interpret 3-way interaction with one continuous variable in mixed model
I have problems interpreting the direction of the effects in my model. Can you help me with this?
I conducted an experiment which includes
between subject factor:
group=2 (coded as 0-1)
within ...
- 689
1
vote
1
answer
2k
views
Converting Bs parameter estimates into Betas
I have unstandadized B coeff.s in my parameter estimates for ANOVA. How can I use Beta=B(SDx/SDy) to convert them into standardized B's (Beta's).
Why doesn't SPSS do this for me, like it does in ...
- 109
2
votes
0
answers
172
views
How to do post-hoc contrasts on within factor depending on certain between groups in SPSS?
Here are my experimental factors:
within-factor (two levels): time1, time2.
between factor (four levels): 4 groups.
I want to test specific post-hoc contrasts comparing:
group1: time1 vs. time2
...
- 460
2
votes
2
answers
8k
views
Multiple dependent variables in factorial design
I have a 2x2x2 factorial design with two dependent variables (lets say height and weight). I can examine the effect of the three factors for each dependent variable separately. But I also want to ...
- 21
3
votes
2
answers
2k
views
Different F-ratios for within subjects effects when using SPSS and R's aov
I've just compared the ANOVA tables generated by SPSS and Statistica with the aov table provided by summary(aov.model). They yield identical between Subject effects (e.g., NativeLanguage(English vs ...
- 51
10
votes
2
answers
22k
views
Understanding repeated measure ANOVA assumptions for correct interpretation of SPSS output
I am investigating whether different reward conditions may affect task performance. I have data from a small study with two groups, each with n=20. I collected data on a task that involved performance ...
- 791
5
votes
2
answers
2k
views
Is SPSS giving the wrong residuals for a repeated measures design?
When running a repeated measures ANOVA in SPSS, it's possible to 'Save' the residuals as new variables in the data editor.
But the values output do not match the residuals given in R, and seem to be ...
- 837
0
votes
2
answers
731
views
What test do I use / how do I show in the analysis that I measured everyone twice?
I have already asked a question on this forum about this, but as I changed my experiment a bit and I am still confused.
I conducted an experiment in which 25 men and 25 women listened to an ...
- 51