- Controlled Investigation
- Field Investigation
- Design Investigation
- Secondary Research Investigation
As we begin to design our independent science investigations, it is important that we understand all of the types of scientific investigations to be best prepared to collect evidence and manage the challenges for our unique investigations.
As we have already learned, a controlled experiment involves changing one thing to observe and measure the effects of that one change. In a controlled experiment, the scientist has total control over the environmental conditions. The temperature, humidity, amount of light, amount of noise, materials, etc. can all be controlled and monitored by the scientist throughout the investigation. For this reason, controlled investigations are usually done indoors, such as in a classroom or kitchen.
Example Controlled Investigation Questions:
- How does the pH of water affect the growth (height) of a fig plant?
- What is the effect of the amount of stuffing in an Oreo on the grams of fat in one Oreo?
A field investigation involves observing and measuring plants and animals (including people) in their natural habitat or environment without changing, harming, or altering the setting or any part of the test subjects. Like in a controlled experiment, the scientist chooses to observe and measure how one change (IV) has a measurable effect (DV) on something else. The key difference is that the scientist does not change anything in the environment, but rather, gathers data on the conditions or situations that already exist.
Example Field Investigation Questions:
- How does the time of day affect the number of fish a penguin eats?
- What is the effect of the temperature in Prospect Park on the number of ducks in Prospect Park Lake?
A design investigation involves changing the design of something (IV) in order to create the effect desired by the scientist. For example, the scientist may wish to design a paper rocket that will travel the furthest distance. Therefore, the scientist might test his/her rocket with 3 different fin lengths. Once he/she has the results of the experiment, the scientist can then create the final product and test it via a controlled experiment to see if it has met the goal.
Example Design Investigation Questions:
- How does the length of the fin on a paper rocket affect the distance the rocket travels?
- What is the effect of the circumference of the wheel on the speed of the wooden car?
A secondary research investigation involves using data (evidence) that has already been gathered by other scientists to answer a question. Therefore, there is no direct "experimenting" done by the scientist in a secondary research investigation. The data that is used can come from the internet, in print, or other sources. The major advantage of secondary research investigations is that the scientist can take advantage of very large data sets that have been gathered over many years or over very large areas. Questions that involve studying long term cause-and-effect relationships (ecosystems, climate, water quality, etc.) may be best suited for this type of investigation.
Example Secondary Research Investigation Questions:
- How does the increase in social media (Facebook, Twitter) use around the world affect the amount of time people spend with their families?
- What is the effect of the increase in carbon dioxide in the Earth's atmosphere on the rate of glaciers melting in the Arctic?
Complete the questions below in your science notebook. Write the questions for #1-7. You do not need to write the questions for #8-12 (just restate and answer in complete sentences for 8-12).
1. What are the four types of scientific investigations?
2. Why are controlled investigations/experiments usually conducted indoors?
3. How is a field investigation like a controlled investigation?
4. How is a field investigation different from controlled investigation?
5. What is a design investigation?
6. Can a secondary research investigation use data from different sources? Explain.
7. What is the major advantage to a secondary research investigation?
8. Jason wants to find out if the members on his soccer team who wear cleats during a game kick the ball further than those who do not wear cleats. What type of investigation will Jason conduct? Explain.
9. Brandon wants to find out what type of video game console heats up to a higher temperature. Brandon will use the exact same game in each console and will play for the exact same amount of time in the same room. What type of investigation will Brandon conduct? Explain.
10. Jennifer wants to know if the amount of sleep people receive over a lifetime has an effect on how long they live. What type of investigation will Jennifer conduct? Explain.
11. Alec wants to find out how the circumference of his skateboard wheels affects his speed. Alec tests out three different wheel sizes. What type of investigation will Alec conduct? Explain.
12. Ms. Shon wants to know if the amount of rainfall has an effect on the number of roses that grow on her rose bush. What type of investigation will Ms. Shon conduct? Explain.