Data Management Research Methods Professional Development Institute December 4, 2015

What is data management?

Data management Codebook Cleaning and checking the data Dataset Construction

Why does it matter Messy data=messy results Record of process, steps

Step One Document everything

Step two Document everything Be explicit. Be clear. You will thank yourself.

DATASET CONSTRUCTION

Components Name of project and dates Names and location of files Notes about “pre-importing” steps Example: change dates to be consistent in format Final files for analysis

Example: Dataset Construction Files

CLEANING THE DATA

What this consists of Any pre-importing steps Getting the data into your software (SPSS, Stata, SAS, R, etc) Recoding text to numeric if needed Variable renaming if needed* Label variables with full question Value labels Missing values Recodes Scale creation**

Variable Names Short (8 characters or less) Systematic, especially with larger projects

Examples y2t1spark6  Year 2, Time 1, measure=sparks, question=number 6 y4t2cr3  Year 4, Time 2, measure=career readiness, question =number 3

Syntax Examples

CHECKING THE DATA Checking labels Reverse Coding Missing Data Coding Checking Frequencies and Ns

DESCRIPTIVES VARIABLES=y4t2feel10 y4t2feel11 y4t2feel12 y4t2feel13 /STATISTICS=MEAN STDDEV MIN MAX.

I feel that I am a person of worth, at least equal to others I feel that I have a number of good qualities I feel I do not have much to be proud of All in all, I am inclined to feel that I am a failure *How I feel. RECODE y4t2feel12 y4t2feel13 (5=1) (4=2) (3=3) (2=4) (1=5) INTO rev_y4t2feel12 rev_y4t2feel13. VARIABLE LABELS rev_y4t2feel12 "How I feel12 reverse coded". VARIABLE LABELS rev_y4t2feel13 "How I feel13 reverse coded".

Reverse Coding-Using SPSS Menu Go to Transform, then select “Recode into Different Variables”.

Reverse Coding-Using SPSS Menu Click over the items to reverse code. For each one, create a new name and label. Click “change” when done with each item, then “OK”. Click “Paste” to have the code copied into a Syntax file.

Reverse Coding-Using SPSS Menu You will now see new variables appear at the bottom of the variable list. What’s missing?

Reverse Coding-Using SPSS Menu Value labels! Under the “Values” column, click the little blue dots.

Reverse Coding-Using SPSS Menu Add the values and labels for each numeric value. Be sure to click “Add” after each value. Click “OK” once you have added all the labels.

Reverse Coding-Using SPSS Menu Repeat for each item. SPSS does not have a “Paste” option if you put in Value Labels this way.

DESCRIPTIVES VARIABLES=pydcont1 pydcont2 pydcont3 pydcont4 pydcont5 /STATISTICS=MEAN STDDEV MIN MAX.

Syntax: Missing values pydcont3 (-99).

DESCRIPTIVES VARIABLES=pydcare1 pydcare2 pydcare3 pydcare4 pydcare5 /STATISTICS=MEAN STDDEV MIN MAX.

FREQUENCIES VARIABLES=pydcare1 pydcare2 /ORDER=ANALYSIS. Where is “4”? Where are the value labels?

THE CODEBOOK

Components Name of construct(s) Source of measure Adaptations from source and why List of items and response options Reverse coding of items Scale creation-what items and how (sum total, mean)

Codebook Examples

OTHER USEFUL DOCUMENTS

Other useful documents Study details – Who, What, Where, When, Why, How Psychometrics – Alpha, means and standard deviations, skewness, correlations, etc. Project Files Tracking