The impact of education on income（use spss do some data analysis）
Ivan.YY
ValidityandReliability.pptxValidity and Reliability
Cronbach’s alpha
Cronbach’s alpha is a convenient test used to estimate the reliability, or internal consistency, of a composite score.
Reliability
Say an individual takes a Happiness Survey. Your happiness score would be highly reliable (consistent) if it produces the same or similar results when the same individual re-takes your survey, under the same conditions.
Cronbach’s alpha
Cronbach’s alpha gives us a simple way to measure whether or not a score is reliable.
Cronbach’s alpha
It is used under the assumption that you have multiple items measuring the same underlying construct
Cronbach’s alpha
For the Happiness Survey, you might have five questions all asking different things, but when combined, could be said to measure overall happiness.
Cronbach’s alpha Analysis
Cronbach’s alpha results should give you a number from 0 to 1
Cronbach’s alpha Analysis
The general rule of thumb is that a Cronbach’s alpha of .70 and above is good, .80 and above is better, and .90 and above is best.
Reporting
A measure of sexual knowledge was obtained using an author constructed questionnaire titled the Sexual Hygiene Anxiety and Gripes For Educational and Academic Research (SHAGFEAR). Attached in the Appendix is the questionnaire with a 12 item measure that asked participants to rate the descriptiveness of a series of statements about sexual hygiene on a numerical rating scale of 1 (not at all like me) to 7 (very much like me). Ratings are averaged across all 12 items. Mean for the total sample was 3.00, SD = 2.12, Cronbach’s alpha was .99. Participants scoring greater than 2.44 were classified as having significant sexual dysfunction.
Literature Questionnaire
In the present study, a measure of depression was obtained using revised version of the Beck’s Depression Inventory (BDI-2, Beck, Steer, & Brown, 1996). This 21 item measure asks participants to select statements that are descriptive of how they have been feeling for the past week, including that day. Responses are coded on a scale of 0-4 for level of depressiveness, α = 0.9.
