Table 1.5: Common Strategies Developmentalists Use to Measure Specific Variables (Behaviors or Concepts of Interest)

Type	Strategy	Commonly Used Ages	Pluses and Problems
Naturalistic observation	Observes behavior directly; codes actions, often by rating the behavior as either present or absent (either in real life or the lab)	Typically during childhood, but also used with impaired adults	Pluses: Offers a direct, unfiltered record of behavior Problems: Very time intensive; people behave differently when watched
Self-reports	Questionnaires in which people report on their feelings, interests, attitudes, and thoughts	Adults and older children	Pluses: Easy to administer; quickly provides data Problems: Subject to bias if the person is reporting on undesirable activities and behaviors
Observer reports	Knowledgeable person such as a parent, teacher, or trained observer completes scales evaluating the person. Sometimes peers rank the children in their class	Typically during childhood; also used during adulthood if the person is mentally or physically impaired	Pluses: Offers a structured look at the person’s behavior Problems: Observers—in particular teachers and parents—have their own biases
Table 1.5 Belsky, Experiencing The Lifespan, 4e © 2016 Worth Publishers