An article entitled "Courtship in the Monogamous Convict Cichlid; What Are Individuals Saying to Rejected and Selected Mates?" considered courtship behavior of male and female damselfish. The author writes, "I randomly selected 12 videotaped trials for analysis of courtship behaviour. When I collected data from the videotapes, I had no knowledge of which male was ultimately selected for the particular tank I was watching."40 Was this done to avoid the placebo effect, the experimenter effect, the problem of faulty memory in retrospective studies, or the problem of participants' behavior being influenced in prospective studies?