Structured Observation - Recored specfied range of behaviours in pre-defined categories (observable actions). Involves observation checklists - e.g. tally. More detailed is a coding frame - codes included.
S - Easy to analyse as quantitative data, high reliability. Easy to record as focusing on certain behaviours, reducing researcher bias.
W - Lack of detail as only quantitative data, reducing validity. Can miss important information as coding scheme.
Unstructured Observation - Records a non-specified, wide range of behaviours.
S - Rich, detailed qualitative data as all recorded, increasing validity.
W - Researcer bias as may only note particular behaviours to support aims, reducing validity.