As applied to the social sciences, the observer effect is known as the Hawthorne Effect, which occurs when subjects of a study modify their behaviour because they are aware that they are under observation. On my school board's databases, I found the following article as it applies to nursing:

Watching affects practice.

TITLE: Watching affects practice.

Source:American Nurse. Jul/Aug 2016, Vol. 48 Issue 4, p5-5. 1/4p. 1 Color Photograph.

Document Type: Article

Subjects:

HAND washing

HAWTHORNE effect

INFECTION prevention

Abstract:

The article discusses the role that the Hawthorne effect, or the observer effect, has on medical health care professionals' hand washing and hygiene practices, including in regard to the relationship between hand washing and preventing infections.

I have found an additional research article on the Observer Effect (Hawthorne Effect) in Social Research:

Title: The Hawthorne Effect in community trials in developing countries.

Authors: Barnes, BrendonR. ([email protected])

Source: International Journal of Social Research Methodology. Oct2010, Vol. 13 Issue 4, p357-370. 14p. 1 Chart.

Document Type: Article

Subjects:

REACTIVITY (Chemistry)

POVERTY

EXPERIMENTAL design

SELF-fulfilling prophecy

BIOMASS

TRIALS (Law)

Abstract:

The Hawthorne Effect is relatively common in community intervention trials. Yet, very little is known about it in developing countries where poverty may play an important role in how and why people participate in studies. A quasi-experimental trial with a comparison group designed to evaluate the effectiveness of an indoor air pollution intervention showed evidence of reactivity in rural South Africa. By drawing on post-trial focus group discussions with members of the comparison group (n = 30), this paper explores the reasons why participants improved their behaviours despite not having received the intervention. Results suggest that participants changed their behaviours for three reasons: expectations of gain, misunderstandings of the data collection equipment and a learning effect. In addition to highlighting the role of poverty and miscommunication in influencing reactivity, this paper also offers recommendations to reduce the Hawthorne Effect in impoverished contexts. [ABSTRACT FROM AUTHOR]

To be clear, the Hawthorne Effect, as it's typically used now, refers to a certain subset of possible observer effects - those effects that occur because the study population is aware that they are being observed, and (knowingly or otherwise) change their behavior. Here's a decent article from a few years back on that:

Article McCambridge J, Witton J, Elbourne DRSystematic review of the...

There are other possible observer effects in the social sciences. Well-designed, well-blinded studies can spread the influence of them across various conditions of a study, but does not necessarily actually reduce it.

Cheers,

Todd

You can as well read Benefits of ‘observer effects’: lessons from the field by Torin Monahan and Jilla Fisher Vanderbilt University, USA

Many thanks for all your contributions. I will look into the recommended literature. I had not heard about the Hawthorne Effect before and it will certainly be interesting to read about the it and other possible observer effects.