1.3 Study Guide Flashcards
Explain step 1 of writing a scientific hypothesis and supply its format.
The first step is to find a specific explanation or reason for the phenomenon being tested. The format is ‘The <Phenomenon> is caused by the <Specific>.'</Specific></Phenomenon>
True or False: The format for step 2 of writing a scientific hypothesis is ‘If <Dependent> changes, then <Independent> changes.'</Independent></Dependent>
False (Independent and Dependent Variables are switched)
Scientists want to test how tall trees will grow when planted alone vs directly next to other trees. Write a hypothesis on what the result of the tests may be.
The taller growth of the trees next to each other is due to their need for sunlight causing them to try to grow above each other to receive the most sunlight possible. If trees are planted directly next to each other, then they will grow taller on average than trees planted alone.
Scientists want to test how tall trees will grow when planted alone vs directly next to other trees. Name 3 variables that must be kept the same between experiments to ensure accurate results.
Possible answers: Water, Sunlight/Lighting, Soil Type, Air Quality, Fertilizer (if given), Species of Tree, etc.
An experiment is testing if dyeing water different colors affects its temperature over time (in hours) while in the sun. What are the Independent and Dependent Variables? What would the Control Group look like and why?
The Independent Variable is the water color and the Dependent Variable is the temperature of the water after being left in the sun for a given number of hours. The Control Group would be non-dyed water to make it clear whether the dyed waters actually heat up differently than regular water.
What is the purpose of a Control Group? How does it differ from an Experimental Group?
The purpose of a Control Group is to represent the phenomenon being tested without applying any change, which shows if the independent variable actually affects anything. It is different from Experimental Groups, which all have some change applied to them.
How many Control Groups are there in a normal controlled experiment? How many Experimental Groups can there be?
In a normal controlled experiment, there is exactly 1 Control Group. Moreover, there can be as many Experimental Groups as needed, but there must be at least 1.
True or False: The definition of
an Experimental Group is “a standard to which comparisons are made in an experiment.”
False. That is the definition of a Control Group.
In an experiment where 2 data sets are being compared, one data set has an average of 5.8 and a standard deviation of 0.7 while the other set has an average of 7.9 and a standard deviation of 3.2. Based on this information, is there a substantial difference between the two data sets? Why or why not?
There is not a substantial difference because the standard deviations of the sets overlap heavily (7.9+or-3.2=4.7 and 11.1 respectively while 5.8+or-0.7=5.1 and 6.5 respectively). This shows that the overall data is relatively similar between each set despite their different averages.
What does standard deviation represent in a data set? What can it show when comparing multiple data sets?
Standard deviation represents how spread out individual pieces of data are in a data set. The standard deviations of multiple data sets show if there is truly a sizable difference between the sets, something their means will not always show.
