SPSS Statistics

 View Only

 repeated-measures linear mixed model in SPSS

Emanuel Festino's profile image
Emanuel Festino posted Wed August 06, 2025 08:49 AM

Hi all,
I’m currently working on a dataset and struggling to properly set up a repeated-measures linear mixed model in SPSS, and I would greatly appreciate your guidance.


In my study, the dependent variable is jump performance. Each participant has four repeated measurements, resulting from a combination of two factors:
• Time: pre and post intervention
• Leg: dominant and non-dominant

So for each subject, I have:
• pre-dominant
• pre-non-dominant
• post-dominant
• post-non-dominant

These conditions are stored in two separate columns: one indicating the leg (dominant vs. non-dominant) and one for time (pre vs. post). My aim is to evaluate whether a specific type of training intervention had an effect on jump performance, considering both leg and time as repeated factors.

When i insert subjcet as random effect i have problem: 

The final Hessian matrix is not positive definite although all convergence criteria are satisfied. The MIXED procedure continues despite this warning. Validity of subsequent results cannot be ascertained.


In attachment you can find my out results output, and photo about my dataset and how I specify the variables