Answer:
Testing hypotheses and identifying variables
Step-by-step explanation:
Option A, testing hypotheses and identifying variables, is not typically part of descriptive or comparative investigations. Descriptive investigations are used to observe and describe a phenomenon, while comparative investigations are used to compare two or more phenomena. Therefore, developing a hypothesis and identifying variables to be tested is not usually a part of these types of investigations.
Options B, using tools and making inferences, and D, making observations and collecting data, are typically part of both descriptive and comparative investigations. The use of tools helps to collect data more accurately and efficiently, and making inferences involves interpreting the data to draw conclusions. Making observations and collecting data are essential steps in both descriptive and comparative investigations.
Option C, asking questions and forming conclusions, is also typically part of both descriptive and comparative investigations. The questions asked can help guide the investigation, and forming conclusions is an important step in analyzing the results of the investigation.
In summary, the step that is not typically part of descriptive or comparative investigations is testing hypotheses and identifying variables.