What type of observations in public spaces does not typically require informed consent?

Naturalistic observations in public spaces typically do not require informed consent because they involve observing individuals in their natural environment where there is an expectation of privacy. In public settings, people generally understand that they may be observed by others, which decreases the ethical obligation for researchers to seek consent. The aim of naturalistic observations is to gain insights into behavior as it occurs in real-world contexts, and as long as the observations do not disturb or significantly invade personal privacy, they can ethically be conducted without prior informed consent.

In contrast, private conversations, controlled research settings, and surveys that include identifiers often do require informed consent due to the potential for privacy infringement and the ethical obligation to respect individuals' autonomy.