12.07.2015 Views

Download - HSRC Press

Download - HSRC Press

Download - HSRC Press

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

2. The first comprehensive discussion of the concept external validity andthreats to external validity appeared in Campbell and Stanley (1963).Cook and Campbell (1979) subsequently presented a more detaileddiscussion. Good discussions of this concept may also be found in Smith(1975) and in Denzin (1978).3. For a general introduction to different types of research designs thefollowing texts may be consulted: Bogue (1981), Drew (1980), Kazdin(1980), Leedy (1980), Nesselroade and Bakes (1979), Selltiz et al. (1965),Smith (1975), and Spector (1981). A few of the texts that are available onthe topic of experimental design are: Chapin (1974), Christensen (1980),Das (1979), Finney (1974), Keppel (1973), and Myers (1979).Free download from www.hsrcpress.ac.za123

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!