If a researcher conducting an experiment shakes his head no or nods his head yes eliciting a change in a response from the test subject, the researcher is exhibiting which phenomenon?

Placebo-controlled study - Wikipedia, the free encyclopedia

As one early clinical trial researcher wrote, "the first object of a ... response can also prove to be an index of how much the treatment has been ... read more on WikiPedia

How would I test this experiment?

I decided to do an experiment on testing if temperatures increase the speed of sound waves. I do have a pretty good idea to test this out but I'm not if its as affective. The easiest way to test this experiment out is to find a warm environment and to to see the speed of sound waves by using a sound level meter. Then I would do the same for a cold enviroment and compare results. However, I'm not sure if this will work exactly and I want to know is there any other way how I can test this experiment in a more creative way. Help please! read more on Yahoo answers

The Mind of a Web Researcher - a knol by Henry Marcos

The Mind of a Web Researcher:How to work like a web researcher [Internet] ... In this article, I would like to cite some points on what does it take to be a ... read more on Google Knol