Final answer:
The researcher's activity is an example of indirect, disguised observation.
Step-by-step explanation:
The researcher standing in the toy section of a retail store and using a checklist to note the sequence in which small children handle the toys is an example of indirect, disguised observation. Indirect observation refers to observing behavior without directly interfering or manipulating the situation, and disguised observation means that the researcher is not readily identifiable as an observer.