external panel - Quality check

Question

Exists a PHP code that checks if participants do not always give the same answer to a question with multiple items?

Looking forward to your response

Answer 1

You can use valueSD() for that - but honestly, this is a very poor quality measure, see https://ojs.ub.uni-konstanz.de/srm/article/view/7403

Comments

Thanks for the tip, but in my case it is very useful.

here it says:
$sd = valueSD('AB01');
if ($sd == 0) {
  goToPage('end');
}

Do I understand it correctly that 0 is a specific variable?


In my case: I have 1 item with 24 scalas and 7 possible answers / variables.

Can I code it for the item with all 7 variables? Actually I dont know how.... Can you pls help me this issue?

Many thx in advance.

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> Do I understand it correctly that 0 is a specific variable?

No, the ==0 just says: If there is no (zero) variance (and therefore not standard deviation) in the items/values of 'AB01' (see thhe first code line with valueSD()), than go the page "end" page.

> I have 1 item with 24 scalas and 7 possible answers / variables.

You mean one scale with 24 items? Or 24 scales, each with 7 items?

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Ok, thx. Now it works :-).