In all scientific investigations, there are observations, data, and conclusions. However, not all scientific investigations are experiments. For an investigation to be an experiment, there must be a test variable (independent), outcome variables (dependent), and __________ variables. Investigations can also be comparative. These investigations observe groups in different conditions and compare the data. There __________ test and outcome variables, but no controls. In descriptive investigations, the observer records information and makes conclusions based on the data. There __________ of any kind, and comparisons are not made between objects or groups.
confined
might be
continuous
controlled
are always
are no variables