I came across this diagram which I thought might be useful (you can see it more clearly in the when you press ‘continue reading’). It is from Ainsworth et al. (1978) page 34. Ainsworth designed the Strange Situation to be conducted in a very specific environment, as shown in this picture. It was a room 9 x 9 foot squares divided into 16 square to record the infant’s movements.
This study is an interesting example of classifying research according to research method. What is it? It was/is conducted in a contrived environment (a laboratory). Data is recorded using observational techniques. Variables are manipulated by the researcher (parent leaves, stranger enters etc) and the effect of these manipulations is recorded (sounds like dependent variables). So is it a controlled observation or a lab experiment?
Also, if you haven’t seen this already, here’s a nice clip of the Strange Situation in action.