Help I can't run Independent-sample t test using SPSS

#1
Hello,

I don't know what's wrong but I've been trying to compare the means of two independent groups using the independent t test in SPSS but I fail each time I try.

This is the message I get:

Warnings
The Independent Samples table is not produced.


a. t cannot be computed because at least one of the groups is empty.

Anyone help me solve this problem?
 
#3
I can reproduce this error message by defining a group that doesn't exist. So you've selected your test variable(s) and a grouping variable, right? When you complete the "Define Groups" fields, the numbers you choose need to be options for the variable.

When I recreated your error message, I used a grouping variable that has values of 1, 2, or 3. When I defined my groups as 1 and 4, I got the same error message. Adding a value for 4 for my grouping variable did not fix the problem. Therefore, I would conclude that (at least in my dataset) one of the two groups you defined doesn't have any responses in your dataset.
 
#5
Hello, I'm so sorry I didn't connect all the day. I apologise.

In the grouping variable I added the TM (Teaching Method), then when I defined the groups I put 1 and 2. 1= the OM (Old method) and 2=the NM (New Method). The problem I guess is the cut point but I couldn't find it. In the variable view page, I also selected the values value 1=OM and value 2=NM. I defined the type as a string and let the scores "numeric". Below is my data. Column 1: the scores from 1=>17 (students' scores taught using the old method) and from 18=>34 are students' scores taught using the new method. Column 2: Teaching Method=> Old method and New Method

Thanks in advance

S TM
0.00 OM
-1.00 OM
2.00 OM
-1.00 OM
2.00 OM
1.00 OM
0.00 OM
-3.00 OM
-1.00 OM
-2.00 OM
0.00 OM
-1.00 OM
1.00 OM
0.00 OM
2.00 OM
-3.00 OM
-1.00 OM
10.00 NM
6.00 NM
14.00 NM
34.00 NM
42.00 NM
26.00 NM
15.00 NM
16.00 NM
38.00 NM
16.00 NM
24.00 NM
36.00 NM
25.00 NM
38.00 NM
30.00 NM
30.00 NM
31.00 NM
 

Masteras

TS Contributor
#6
the type as string? the type is also numeric. What you will do for the type is go to the last column of this tab and choose nominal. Now do the t-test again. But obviously there is no need to perform it, the result is obvious.
 
#7
Thank you very much for your help.

I got a similar warning message: a. t cannot be computed because at least one of the groups is empty.

I tried what you told me, I changed the TM type from string into numeric but the OM and NM labels disappeared :shakehead and I couldn't perform the test.

The 1st column of scores is numeric and the measure is scale.
The 2nd column of TM is string (when I change it to numeric the value labels are cleared) and the measure is nominal....Is that correct?!!

This is really tiring me out I've been trying to fix that for days. :confused:

Many Thanks
 
#10
Hello Dear

I have a problem is SPSS. I can't run Independent-sample t test using SPSS. SPSS give me this error:

The Independent Samples table is not produced.

null null a. t cannot be computed because at least one of the groups is empty.


The data is as following:

10.67 6.00
7.78 4.00
4.28 3.00
9.03 3.00
6.43 2.00
4.25 3.00
2.42 1.00
11.73 7.00
5.28 4.00
9.12 6.00
8.93 5.00
7.50 5.00

I done: after input data > Analyze > Compare Means > Independent-sample t test > Define Group 1 and 2 > Ok

Please Help me.
Tq.
 

Masteras

TS Contributor
#11
you need to put these columns in one. And then have a second one where you say 1 1 1 1 1 1 and 2 2 2 2 2 2 . the second defines the two groups.
 

Karabiner

TS Contributor
#12
You told SPSS to use the second row as grouping variable? And you used "1" and "2"
for defining the two groups? That seems to make not much sense, since in each group
there is only 1 case.

Regards

K.
 
#13
Hi there,
I'm getting the exact same error, can someone help troubleshoot?
Attached is the file below
Section QuizGrade
1.00 100.00
1.00 33.00
1.00 92.00
1.00 33.00
1.00 98.00
1.00 55.00
1.00 100.00
1.00 99.00
1.00 57.00
1.00 72.00
1.00 50.00
1.00 100.00
1.00 100.00
1.00 92.00
1.00 85.00
1.00 76.00
1.00 52.00
1.00 52.00
1.00 89.00
1.00 95.00
2.00 95.00
2.00 100.00
2.00 88.00
2.00 85.00
2.00 97.00
2.00 80.00
2.00 75.00
2.00 99.00
2.00 95.00
2.00 100.00
2.00 66.00
2.00 82.00
2.00 85.00
2.00 85.00
2.00 90.00
2.00 92.00
2.00 90.00
2.00 87.00
2.00 95.00
2.00 99.00