SPSS Results Unavailable for ANCOVA?

More Arthur Crombez's questions See All

Which test should I use?

Hi, I am wondering which test should I run To summarize quickly my experiment, people were instructed to select some products. Some products where organic and others not. The proportion of...

27 May 2019 8,826 3 View

Which test should I use?

Hi, I am wondering which test should I run To summarize quickly my experiment, people were instructed to select some products. Some products where organic and others not. The proportion of...

04 May 2019 3,224 4 View

error in running a model in Abaqus

Excessive rotation of nodes in node set ErrNodeExcessRotation-Step1

17 August 2021 0 0 View

error in modelling model in Abaqus

Excessive rotation of nodes in node set ErrNodeExcessRotation-Step1

17 August 2021 0 0 View

MGL tools

20 June 2021 0 0 View

i have some problem with chtMultiRegionSimpleFoam

--> FOAM FATAL ERROR: Maximum number of iterations exceeded From function Foam::scalar Foam::species::thermo::T(Foam::scalar, Foam::scalar, Foam::scalar, Foam::scalar (Foam::species::thermo::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo::*)(Foam::scalar) const) const [with Thermo = Foam::hConstThermo >; Type = Foam::sensibleEnthalpy; Foam::scalar = double; Foam::species::thermo = Foam::species::thermo >, Foam::sensibleEnthalpy>] in file /home/ubuntu/OpenFOAM/OpenFOAM-4.1/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 66. FOAM aborting #0 Foam::error::printStack(Foam::Ostream&) at ??:? #1 Foam::error::abort() at ??:? #2 Foam::heRhoThermo >, Foam::sensibleEnthalpy> > > >::calculate() at ??:? #3 Foam::heRhoThermo >, Foam::sensibleEnthalpy> > > >::correct() at ??:? #4 ? at ??:? #5 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #6 ? at ??:?

24 March 2021 0 0 View

How to compare two groups with only two measurements?

Hiiiii everyone! I have an enquiry on statistical analysis. I was looking for many forum and it's still cannot solve my problem. I want to compare means of two groups of data but only with two...

03 March 2021 8,796 3 View

Binary Logistic Generalized Linear Mixed model in SPSS. Is it doable?

I want to analyses the proportion of swimming sperm of three species of fish in two salinities. To analyse the proportion of swimming sperm in a Generalized Linear Model, I would use a Binary...

03 March 2021 2,297 3 View

What's the best way to measure growth rates in House sparrow chicks from day 2 to day 10?

What's the best way to measure growth rates in House sparrow chicks from day 2 to day 10? Since, the growth curve from day 2 to 10 won't be like the "Logistic curve" it might not follow logistic...

03 March 2021 1,401 3 View

What test should i use in comparing the correlation between categorical and continuous variables?

Dear all, I have the variable (Surgery duration) represented by values in minutes and the variable (preoperative neuropraxia cases) represented as (Yes/No) values. I want to compare these two...

03 March 2021 5,427 5 View

Logistical regression using SPSS for a dichotomous dependent variable, with an independent variable of 1, 2, 5 and 10 seconds?

I have an experiment with 28 participants The independent variable is the times 1, 2, 5, and 10 used as the cross hairs during a task These 4 times were tested using 4 different blocks, each...

03 March 2021 9,692 2 View

How to find the mean, SD and CI in SPSS?

Hi, I hope that someone can help me with this task: I have 5 groups of participants which are numbered in SPSS from 1 to 5 (according to their group number) and are all under the variable group....

03 March 2021 506 3 View

Thom S Baguley

Hard to say exactly - but it looks like there is no variation in some of your variables.

I'd start by looking at your descriptive statistics for each variable (M and SD) and then look at correlations to see if any of them are perfectly collinear.

Timo Törmäkangas

Your error sum of squares is zero. The F-statistic uses this as the denominator resulting in division by zero. This implies that some of the independent variables sum exactly the dependent variable. Is number of products selected = Total Healthy + Total Unhealthy (+ some constant)?

Best regards,

Gerontology Research Center

University of Jyväskylä

Finland

Arthur Crombez

Timo Törmäkangas Hi! Thank you for your help. Yes it's.

I tried to do another analysis (one-way repeated measures ANOVA) with covariates but I'm unsure how should I analyze the results. Can u help on this?

Rainer Duesing

As Timo mentioned, the problem was that the model was perfectly specified by number of healthy products selected / number of unhealthy products selected since they are perfectly dependent on each other with regard to the dependent variable, which is simply the sum of both. So, what should this predictors add as information to your model?!?!

For your second model: this model seems more plausible, BUT with the information given about the dependent variable, it sounds as if you have a count variable and not a continous variable, since values below zero and fractions are not possible (only integers). In this case, the ordinary least squares regression is not the correct statistical model (in most cases), since the residuals will most often not follow a normal distribution (check this point) and the distribution of the means is possibly not linear. Typically, suitable models are from the generalized linear models family, e.g. poisson or negative binomial regression with other link functions as the identity link!