Inhoud
WC1 – inleiding.......................................................................................................................................3
WC2 – datamanipulatie..........................................................................................................................3
WC3- samenhang & statistische controle...............................................................................................4
Samenhang.........................................................................................................................................4
Tabelsplitsing......................................................................................................................................4
WC5 – covariantie, correlate & bivariate regressive...............................................................................4
Samenhang.........................................................................................................................................4
Scatterplot......................................................................................................................................4
Covariantie & Pearson product-moment correlatiecoëfficiënt.......................................................4
Bivariate regressie..............................................................................................................................5
Regressierechte..............................................................................................................................5
Bivariate regressie..........................................................................................................................5
WC6 – meervoudige regressie................................................................................................................6
Voorbereidende bivariate analyses.....................................................................................................6
Gegevens en operationalisering.....................................................................................................6
Meervoudige regressie.......................................................................................................................7
Stijging in verklaarde variantie opvragen........................................................................................7
WC7 – regressiediagnostiek....................................................................................................................7
Schending lineariteitsassumptie.........................................................................................................7
Additiviteistassumptie........................................................................................................................7
Multicollineariteit...............................................................................................................................7
Homoskedasticiteit.............................................................................................................................8
Normaliteitsassumptie.......................................................................................................................8
Outliers en hefboompunten...............................................................................................................8
WC8 - Dummy-regressie.........................................................................................................................9
Dummy-regressie................................................................................................................................9
Modellen met interactie.....................................................................................................................9
WC9 – Variantie-analyse.........................................................................................................................9
Van t-test naar variantie-analyse........................................................................................................9
One-way analysis of variance............................................................................................................10
Bonferroni post-hoc test...................................................................................................................11
N-way analysis of variance en analysis of covariance.......................................................................11
Effectcodering...................................................................................................................................12
WC10 – Logistische regressie................................................................................................................13
1
, Logistische regressie.........................................................................................................................13
Hosmer-lemeshow test.....................................................................................................................13
WC11 – Padanalyse..............................................................................................................................14
WC11 – multinominal logit modellen...................................................................................................14
Multinominale regressie...................................................................................................................14
WC12 – Principale componentenanalyse & PFA...................................................................................15
Principale componentenanalyse.......................................................................................................15
Rotatie van de componenten............................................................................................................15
Orthogonale rotatie......................................................................................................................15
Oblieke rotatie..............................................................................................................................17
Betrouwbaarheidsanalyse (Cronbach’s Alpha).................................................................................17
Somscores.........................................................................................................................................18
Zelf somscore aanmaken..............................................................................................................18
Factorscores laten bereken door stata..........................................................................................18
2
, WC1 – inleiding
Verwijderen van een variabele drop …
Frequentietabel opvragen tab1 …, miss
Histogram maken graphics > histogram
o Y- axis : frequency
o Bar properties
o Normaalcurve toevoegen: density plot
o Titel toevoegen
Gemiddelde bepalen summarize …
o Opgelet ! code 9999 wordt meegerekend
o Oplossing: code 9999 omzetten naar missing value mvdecode …, mv(9999)
Kwartielen opvragen tabstat …, statistics (p25 p50 p75)
WC2 – datamanipulatie
Centreren van een variabele + nieuwe variabele aanmaken
o Gemiddelde bepalen summarize …
o Nieuwe variabele aanmaken generate … = … - gemiddelde
Variabele hercoderen naar categorieën recode … (…=0)(…=1), generate (…)
Gemiddelde indien filter summarize … if …
Variabele standaardiseren
o Gemiddelde & standaardafwijking bepalen summarize ….
o Nieuwe variabele aanmaken generate … = (…-gem)/st.afw.)
Variabele dummificiëren
o Nieuwe variabele aanmaken recode …, generate (…)
Schaal aanmaken
o Freq. Tabel opvragen van alle variabelen tab1 …, miss
o Waarde als missing definiëren mvdecode …, mv(…)
o Schaal omkeren recode …, prefix (rev_...)
o Aantal valide waarde bepalen egen float … = rowmean(rev_...) if…
o Schaalvariabele aanmaken egen float … = rowmean(…) if …
3
WC1 – inleiding.......................................................................................................................................3
WC2 – datamanipulatie..........................................................................................................................3
WC3- samenhang & statistische controle...............................................................................................4
Samenhang.........................................................................................................................................4
Tabelsplitsing......................................................................................................................................4
WC5 – covariantie, correlate & bivariate regressive...............................................................................4
Samenhang.........................................................................................................................................4
Scatterplot......................................................................................................................................4
Covariantie & Pearson product-moment correlatiecoëfficiënt.......................................................4
Bivariate regressie..............................................................................................................................5
Regressierechte..............................................................................................................................5
Bivariate regressie..........................................................................................................................5
WC6 – meervoudige regressie................................................................................................................6
Voorbereidende bivariate analyses.....................................................................................................6
Gegevens en operationalisering.....................................................................................................6
Meervoudige regressie.......................................................................................................................7
Stijging in verklaarde variantie opvragen........................................................................................7
WC7 – regressiediagnostiek....................................................................................................................7
Schending lineariteitsassumptie.........................................................................................................7
Additiviteistassumptie........................................................................................................................7
Multicollineariteit...............................................................................................................................7
Homoskedasticiteit.............................................................................................................................8
Normaliteitsassumptie.......................................................................................................................8
Outliers en hefboompunten...............................................................................................................8
WC8 - Dummy-regressie.........................................................................................................................9
Dummy-regressie................................................................................................................................9
Modellen met interactie.....................................................................................................................9
WC9 – Variantie-analyse.........................................................................................................................9
Van t-test naar variantie-analyse........................................................................................................9
One-way analysis of variance............................................................................................................10
Bonferroni post-hoc test...................................................................................................................11
N-way analysis of variance en analysis of covariance.......................................................................11
Effectcodering...................................................................................................................................12
WC10 – Logistische regressie................................................................................................................13
1
, Logistische regressie.........................................................................................................................13
Hosmer-lemeshow test.....................................................................................................................13
WC11 – Padanalyse..............................................................................................................................14
WC11 – multinominal logit modellen...................................................................................................14
Multinominale regressie...................................................................................................................14
WC12 – Principale componentenanalyse & PFA...................................................................................15
Principale componentenanalyse.......................................................................................................15
Rotatie van de componenten............................................................................................................15
Orthogonale rotatie......................................................................................................................15
Oblieke rotatie..............................................................................................................................17
Betrouwbaarheidsanalyse (Cronbach’s Alpha).................................................................................17
Somscores.........................................................................................................................................18
Zelf somscore aanmaken..............................................................................................................18
Factorscores laten bereken door stata..........................................................................................18
2
, WC1 – inleiding
Verwijderen van een variabele drop …
Frequentietabel opvragen tab1 …, miss
Histogram maken graphics > histogram
o Y- axis : frequency
o Bar properties
o Normaalcurve toevoegen: density plot
o Titel toevoegen
Gemiddelde bepalen summarize …
o Opgelet ! code 9999 wordt meegerekend
o Oplossing: code 9999 omzetten naar missing value mvdecode …, mv(9999)
Kwartielen opvragen tabstat …, statistics (p25 p50 p75)
WC2 – datamanipulatie
Centreren van een variabele + nieuwe variabele aanmaken
o Gemiddelde bepalen summarize …
o Nieuwe variabele aanmaken generate … = … - gemiddelde
Variabele hercoderen naar categorieën recode … (…=0)(…=1), generate (…)
Gemiddelde indien filter summarize … if …
Variabele standaardiseren
o Gemiddelde & standaardafwijking bepalen summarize ….
o Nieuwe variabele aanmaken generate … = (…-gem)/st.afw.)
Variabele dummificiëren
o Nieuwe variabele aanmaken recode …, generate (…)
Schaal aanmaken
o Freq. Tabel opvragen van alle variabelen tab1 …, miss
o Waarde als missing definiëren mvdecode …, mv(…)
o Schaal omkeren recode …, prefix (rev_...)
o Aantal valide waarde bepalen egen float … = rowmean(rev_...) if…
o Schaalvariabele aanmaken egen float … = rowmean(…) if …
3
