Get started entering and preparing data for analysis
BEEC
Dr. Christine Pereira Academic Skills Team (ASK) ask@brunel.ac.uk
Identify, define & enter variables in your survey
Import online survey data from Excel
Recode variables
Reliability test using Cronbach’s alpha
Compute a total score and mean score
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Dr. Christine Pereira
ASK Academic Skills (2014-15)
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What is your main mode of transport to Uni during the week?
What is your age? (please tick one)
Car Bus Tube Rail Walk Cycle
1 2 3 4 5 6
1
18-25 26-35 36-45 46-55 56+
(please tick one)
Codes
2 3 4 5
Codes
Codes
What is your gender? (please circle one)
0
1
Male
Female
Each question is a new variable. Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Gender
Age Group
Mode
1
Male
36-45
Car
2
Male
26-35
Tube
Female
46-55
Car
4
Male
18-25
Tube
5
Female
26-35
Rail
0 3= Male 1 = Female
Each question is a new variable. Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Gender
Age Group
Mode
1
0
36-45
Car
2
0
26-35
Tube
1
46-55
Car
4
0
18-25
Tube
5
1
26-35
Rail
0 3= Male 1 = Female
Each question is a new variable. Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Gender
Age Group
Mode
1
0
36-45
Car
26-35
Tube
46-55
Car
18-25
Tube
26-35
Rail
2 3 4 5
1 =018-25 2 = 26-35 3 =136-45 4 = 46-55 5 =055+ 1
Each question is a new variable. Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Gender
Age Group
Mode
1
0
3
Car
2
Tube
4
Car
1
Tube
2
Rail
2 3 4 5
1 =018-25 2 = 26-35 3 =136-45 4 = 46-55 5 =055+ 1
Each question is a new variable. Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Gender
Age Group
Mode
1
0
3
Car
2
0
3
1
4
0
5
1
1 = Car 2 2 = Bus 3 = Tube 4 4 = Rail 5 = Walk 1 6 = Cycle 2
Tube Car Tube Rail
Each question is a new variable. Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Gender
Age Group
Mode
1
0
3
1
2
0
3
1
4
0
5
1
1 = Car 2 2 = Bus 3 = Tube 4 4 = Rail 5 = Walk 1 6 = Cycle 2
3 1 3 4
Each question is a new variable. Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Which mode(s) of transport do you usually take to get to Uni during the week? (please tick all that apply) Car Bus Tube Rail Walk Cycle
Dr. Christine Pereira
‘tick all…’ instead of ‘tick one’
ASK Academic Skills (2014-15)
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Participant
Transport
1
Car
2
Bus, Tube
3
Car
4
Tube, Rail, Walk
5
Bus, Rail
Dr. Christine Pereira
Can we enter responses like this?
ASK Academic Skills (2014-15)
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Participant
Transport
1
Car
2
Bus, Tube
3
Car
4
Tube, Rail, Walk
5
Bus, Rail
Dr. Christine Pereira
Can we enter responses like this?
ASK Academic Skills (2014-15)
Why not?
13
Participant
Transport
1
Car
2
Bus, Tube
3
Car
4
Tube, Rail, Walk
5
Bus, Rail
Can we enter responses like this? Why not?
Only ONE response per cell for statistical analysis Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Which mode(s) of transport do you usually take to get to Uni during the week? (please tick all that apply) Q1 Q2 Q3 Q4 Q5 Q6
Car Bus Tube Rail Walk Cycle
Dr. Christine Pereira
Codes 0 = No 1 = Yes
ASK Academic Skills (2014-15)
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Participant
Car
Bus
Tube
Rail
Walk
Cycle
1
Yes
No
No
No
No
No
2
No
Yes
Yes
No
No
No
3
Yes
No
No
No
No
No
4
No
No
Yes
Yes
Yes
No
5
No
Yes
No
Yes
No
No
Each response is a new variable Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Car
Bus
Tube
Rail
Walk
Cycle
1
Yes
No
No
No
No
No
2
No
Yes
Yes
No
No
No
3
Yes
4
No
No
Yes
Yes
Yes
No
5
No
Yes
No
Yes
No
No
Yes = They travel by car No No No No No = They do not travel by car
No
Each response is a new variable Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Car
Bus
Tube
Rail
Walk
Cycle
1
Yes
No
No
No
No
No
2
No
Yes
Yes
No
No
No
3
Yes
No
4
No
No
Yes
Yes
Yes
No
5
No
Yes
No
Yes
No
No
Yes = They travel by bus No No No No No = They do not travel by bus
Each response is a new variable Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Car
Bus
Tube
Rail
Walk
Cycle
1
Yes
No
No
No
No
No
0 =2No 1 =3Yes
No
Yes
Yes
No
No
No
Yes
No
No
No
No
No
4
No
No
Yes
Yes
Yes
No
5
No
Yes
No
Yes
No
No
Each response is a new variable Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Car
Bus
Tube
Rail
Walk
Cycle
1
1
0
0
0
0
0
0 =2No 1 =3Yes
0
1
1
0
0
0
1
0
0
0
0
0
4
0
0
1
1
1
0
5
0
1
0
1
0
0
Each response is a new variable Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Obtain preferential judgements or opinions. Rank in order of importance, from 1-5, the following features when considering a destination for your holiday.
Rank the following subjects from 1-5 based on how much you like them. (1 = Favourite, 5 = Least favourite)
(1 = Most important) Q1 Q2 Q3 Q4 Q5
History Science Math Writing IT
Codes 1 = Favourite 2–4 5 = Least favourite
I’ve never been before Weather Surroundings Cost Accommodation
These are also multiple response questions Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Obtain preferential judgements or opinions. Rank in order of importance, from 1-5, the following features when considering a destination for your holiday.
Rank the following subjects from 1-5 based on how much you like them. (1 = Favourite, 5 = Least favourite)
(1 = Most important)
History Science Math Writing IT
Codes 1 = Most important 2–5
Q1 Q2 Q3 Q4 Q5
I’ve never been before Weather Surroundings Cost Accommodation
These are also multiple response questions Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Never been
Weather
Surroundings
Cost
Accommodation
1
Most Impt
4
2
3
5
2
5
2
3
Most Impt
4
3
5
Most Impt
2
4
3
1 = Most important 4
3
4
5
Most Impt
2
5
4
2
Most Impt
5
3
Each response is a new variable Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Never been
Weather
Surroundings
Cost
Accommodation
1
1
4
2
3
5
2
5
2
3
1
4
3
5
1
2
4
3
1 = Most important 4
3
4
5
1
2
5
4
2
1
5
3
Each response is a new variable Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Obtain preferential judgements or opinions Likert scale: Level of agreement
Other scales: Level of importance or satisfaction
How important are the following when considering where to live?
(circle one)
Very Important
Important
I don’t know
Unimportant
Very Unimportant
Q1
Cost
1
2
3
4
5
Q2
Distance to Uni
1
2
3
4
5
Q3
Distance to work
1
2
3
4
5
Q4
I feel safe
1
2
3
4
5
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Cost
Dist Uni
Dist Work
Safety
1
Very Impt
Important
I don’t know
Important
Very Impt
Very Impt
Important
Very Impt
Important
Very Impt
I don’t know
Important
Important
Important
Important
Very Impt
1 = Very 2 Impt Important 2 = Important 3 = I don’t know Unimportant 3 4 = Unimportant 4 Unimpt Unimportant 5 = Very 5
Very Impt
Each question is a new variable. Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Participant
Cost
Dist Uni
Dist Work
Safety
1
1
2
3
2
2
1
1
2
2
1
2
1
2
3
2
2
1
2
2
1
1 = Very 2 Impt 2 = Important 3 = I don’t know 3 4 = Unimportant 4 Unimpt 5 = Very 5
Each question is a new variable. Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Uncoded data Downloaded from online survey
Coded data Downloaded from online survey Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Uncoded data Downloaded from online survey
Download coded responses if possible! Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Open ended question so not coded by online survey
Dr. Christine Pereira
You need to code these yourself
ASK Academic Skills (2014-15)
1 2 3 4 5 6 7 8 9 10 11 12
USA Brazil Cambodia China Fiji France Greece India New Zealand Peru Thailand Vietnam
35
We don’t need this info for analysis
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Put variable names in Row 1
Data starts in Row 2
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Data is ready to be imported to SPSS
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Existing data file
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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3
Find the folder where you saved the file
Select the Excel file
1 Dr. Christine Pereira
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Choose Excel file type to see your .xlsx ASK Academic Skills (2014-15)
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Choose the correct worksheet
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Variable Names (from Row 1)
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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• These variable names from Excel couldn’t be used • SPSS made them labels and created a new variable name
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Put in LABELS Put in VALUES for nominal/ordinal variables
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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This is not correct!
You need to fix it after import
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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http://www.statstutor.ac.uk/resources/uploaded/importdatav20.mp4 Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Not importing your data? Entering it all by hand?
Watch these short videos to learn how to enter your own data
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Dr. Christine Pereira
Current coding
Reverse coding
OLD value
NEW value
1
Strongly Disagree
5
Strongly Disagree
2
Disagree
4
Disagree
3
Undecided
3
Undecided
4
Agree
2
Agree
5
Strongly Agree
1
Strongly Agree
ASK Academic Skills (2014-15)
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Select variable to recode
Selected variable
Click
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Name and Label new variable
New variable
Click
Lastly Click here Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Old value
New value
Click ‘Add’
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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What about missing values and missing value codes?
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Our new variable: Satisfaction reverse coded
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Define missing value codes, if any
Define the level of measurement Default values are not always correct Dr. Christine Pereira
ASK Academic Skills (2014-15)
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http://www.statstutor.ac.uk/resources/uploaded/reversecodev20.mp4 Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Dr. Christine Pereira
Current coding
New coding
OLD value
NEW value
1
Strongly Disagree
2
Disagree
3
Undecided
4
Agree
5
Strongly Agree
ASK Academic Skills (2014-15)
Disagree 1 or Strongly Disagree 2
Undecided
3
Agree or Strongly Agree
57
Select variable to recode
Selected variable Click
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Name and Label new variable
New variable
Click
Lastly Click here Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Old value
New value
Click ‘Add’
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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What about missing values and missing value codes?
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Our new variable: Satisfaction regrouped
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Define missing value codes, if any
Put in value labels Define the level of measurement Default values are not always correct Dr. Christine Pereira
ASK Academic Skills (2014-15)
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http://www.statstutor.ac.uk/resources/uploaded/reducegroupsv20.mp4 Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Multi-response variables often need recoding They should all be: 0 = No (currently missing) 1 = Yes (currently 1-6)
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Recode into Same variables Replace: • Numbers 2-7 with 1 • Missing values with 0
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Cronbach’s Alpha measures internal consistency between items in a scale
Make sure not to mix positively and negatively worded questions – Alpha will be negative. Reverse code variables if needed
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Select variables Click
Selected variables
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Click
*Optional: Name the scale Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Dr. Christine Pereira
ASK Academic Skills (2014-15)
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http://youtu.be/NvGG38N0P7c Dr. Christine Pereira
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1
Dr. Christine Pereira
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2
Should be >=.70 If less than 10 items, it should be >0.5 Dr. Christine Pereira
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3
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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4 The correlation of every item in the scale with every other item. Dr. Christine Pereira
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5
The mean inter-item correlation. If Alpha is low (due to few items) report this value too. Dr. Christine Pereira
ASK Academic Skills (2014-15)
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6
Cronbach’s Alpha if the item is removed from the scale. Dr. Christine Pereira
ASK Academic Skills (2014-15)
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http://youtu.be/KODQPg-48jA Dr. Christine Pereira
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Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Name the new variable
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Add variables together with +
Variables in dataset Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Click OK Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Our new variable: Total_LifeSatis
• Total score ONLY calculated for participants with all Life Satis scores • Each blank means that participant was missing 1 or more Life Satis scores
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Define missing value codes, if any
Put in LABELs and VALUES Define the level of measurement Default values are not always correct Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Name the new variable
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Double click
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Replace ? with variable names Put a comma between each variable
Variables in dataset Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Calculates a mean for every participant, even if they are missing 1 or more of the LifeSatis scores
Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Numeric Expression: MEAN.2(LifeSatis1, LifeSatis2, LifeSatis3, LifeSatis4, LifeSatis5)
Calculates a mean for every participant only if they have at least 2 of the LifeSatis scores Numeric Expression: MEAN.3(LifeSatis1, LifeSatis2, LifeSatis3, LifeSatis4, LifeSatis5)
This number can be between 1 & the number of items being averaged Dr. Christine Pereira
Calculates a mean for every participant, only if they have all 3 LifeSatis scores
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Click OK Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Our new variable: Mean_LifeSatis
• Mean score calculated for participants with 1 or more Life Satis scores • Each blank means that participant was missing all Life Satis scores Dr. Christine Pereira
ASK Academic Skills (2014-15)
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Define missing value codes, if any
Put in a LABEL Define the level of measurement Default values are not always correct Dr. Christine Pereira
ASK Academic Skills (2014-15)
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http://www.statstutor.ac.uk/resources/uploaded/computemeanv20-2.mp4 Dr. Christine Pereira
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Dr. Christine Pereira
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