SPSS Statistics

Thank you for your reply. 

we haven't used any log. 

for the DFA or Linear regression I never have to use log to make the prediction equation. I only use continuous data in my own research so I'm a bit at a loss of how to use the transformed variables and come up with the predictive value. 

all the best

Thank you for your reply. 

we haven't used any log. 

for the DFA or Linear regression I never have to use log to make the prediction equation. I only use continuous data in my own research so I'm a bit at a loss of how to use the transformed variables and come up with the predictive value. 

all the best

Thank you for your reply. 

we haven't used any log. 

for the DFA or Linear regression I never have to use log to make the prediction equation. I only use continuous data in my own research so I'm a bit at a loss of how to use the transformed variables and come up with the predictive value. 

all the best

Thank you for your reply. 

we haven't used any log. 

for the DFA or Linear regression I never have to use log to make the prediction equation. I only use continuous data in my own research so I'm a bit at a loss of how to use the transformed variables and come up with the predictive value. 

all the best

Dear Rick

This is very useful. I am still confused what she needs to use as values in the prediction equation. It is usual in our field to publish a prediction equation for others to use on their own data. So another scientist will need to use his/her own scores to solve the equation and the value will then be the sex estimate. 

If I understand it well:

So if we take the example from the link you sent, there were originally 4 categories for the REGION - these have now been turned into region 1, region 2, region 3, and the reference "region" (for those from the 4th category)? Region does not have a coefficient because it is the reference so this will never appear in the equation and individuals who were in the reference category will thus always use a value of 0 if region 1,2 or 3 appears in it? 

REGION
REGION(1) 2.549343
REGION(2) 2.019601
REGION(3) -.281382

So, if the equation has an individual from region 2, then we replace the value of region 2 with value "1" and replace region 1 and 3 with value "0"? 

In our example this would look like: 
sex = 75.8 + (-57.296*1) + (-37.333*0) + (-18.504*1) + (-55.213*0) + (38.256*0) + (-57.519*1) + (-1.946*0) 

We then insert the value of sex (z) into this equation: 1/(1 + EXP(-z))  this should return a value between 1 and 0?

Thank you!

Isabelle

Thank you for your reply. 

we haven't used any log. 

for the DFA or Linear regression I never have to use log to make the prediction equation. I only use continuous data in my own research so I'm a bit at a loss of how to use the transformed variables and come up with the predictive value. 

all the best