Anchor: Site selection cannot be convenience because usually generalization wanted, and purposive sample can be typical and representative of diversity and best and worst cases; number of cases depends on program diversity since generalization usually wanted; data rely on common instruments, published documents, and observation; reports are varied in theme, site, chronology, and narration
Entailed: Sites should not be selected based on convenience.
Contradiction: There are no best and worst cases.
Contradiction: Two men are sitting on the grass.
Contradiction: The box office is open Sunday through Thursday.
Contradiction: Civil suits always involve individuals and you're forced to go before a jury.
Contradiction: The lady is not a teenager.