The videos I watched were about Heavy for Size Investigations.
The scientist has a background that our students do not. We must take this into consideration as they are the experts. The scientist focuses on using objective facts and did not relay on subjective observations or expected outcomes. Although he used the sense of feel (weight), this was just the first step. He also described knowing the difference between volume and weight, materials such as mineral oils versus water, and confirmed his thoughts through a scale. He also used mathematical processes. The scientist also looked at each specimen through a scientific lens where he described the difference between soil being composed of three things (solids, water, and air) versus the liquids being composed of just liquids.
The students in the grade 4: The students struggle with the idea of weight versus density. They also have difficulty determining density when not taking the size of the samples into account. For example, a large piece of aluminum might be mistaken as being more dense than a smaller piece of steel. The kids also may think that density is when things float or sink instead of displacement. The other issue is that children don’t have the experiences of using/feeling the materials that are being discussed.
Using the ideas and misconceptions above, I would definitely want to have the kids exposed to the various materials, handle them, examine them, and make observations. It would be very helpful to have them the same materials in different shapes and sized. I would also expose them to scales and balances, how to read these, and how to accurately record the data. The students would also need to be exposed to content area vocabulary.