Intro to the Scientific Method, Part 3

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Question 1: Can we have more than one experimental group in an experiment?

• No

• Yes

Answer explanation

Yes. There is usually 1 control group but there can be 1 or more experimental groups.

Should a control and experimental group for web page testing be available to customers on the same days?

• No

• Yes

Answer explanation

Yes. The day something is available is a controlled variable and should be the same in all groups.

Is the independent variable the one whose value we set?

• No

• Yes

Answer explanation

Yes. That is how the groups differ.

If we can plot data on a bar or a line graph, is it better to use a bar graph?

• No

• Yes

Answer explanation

No. In general, if we can use line graphs, then we use them (better for math analysis).

Are dependent variables plotted on the y-axis?

• No

• Yes

Answer explanation

Yes. These are also the OUTput numbers on function (IN-OUT) math graphs. INdependent goes on the x-axis.

Are independent variables plotted on the x-axis?

• No

• Yes

Answer explanation

Yes. Independent variable values are plotted on the x-axis.

Are constant variables plotted on the y-axis?

• No

• Yes

Answer explanation

No. Those are rarely plotted. The values for the dependent and independent variables are plotted.

If a line on a line-graph is falling in height when read from left to right, does that mean the trend is increasing?

• No

• Yes

Answer explanation

No. That would show a decreasing trend. An increasing trend has a line’s height that is rising.