What I love the most about any FOSS unit, is that the children DO the activity FIRST and connect the VOCABULARY AFTER they explore. They also come to understand that engineers work at solving problems that come up. They use their knowledge of science to design and build useful things - in this case, designing a system to accurately measure the speed of a ball on a ramp.
This is something that makes PERFECT SENSE to me. I have a classroom that includes ESL, Gifted Ed, LD, ED, Autistic and 504 (ADHD, Hearing Impaired)...yes, I am not kidding! For these kids, plus those without a label (yes, there are some of those kids too!) I have learned that scientific vocabulary as well as process vocabulary "sticks" when you connect it to a real world experience.
I wish I could post a video of the kids talking and discussing science. We had an AMAZING discussion full of "I disagree" statements and "the evidence states..." statements. Unfortunately, that would be showing the kids too much and I don't feel comfortable posting their faces so openly.
However, children are able to use the scientific and engineering vocabulary as they work. You can see them thinking and processing what they are doing as they create. Is this mastery yet? Not yet, but they are on their way. Talking is essential to understanding for many children....and adults. (Including me!)