Science Buddies: "Ask an Expert"

I am doing a science fair project the topic being a burglar alarm. i have finished testing and am up to writing my results and analysing the data for my final report. My question is what do i put in the results table if all I have is one independent variable, type of opening eg. window, door etc., and I haven't measured anything just if the alarm worked on that opening or not?

Hello hannah56,

Your experiment has just one independent variable--which wondow, door, etc. you tested, and one dependent variable--did it work, yes or no.

This is a bit different than conducting an experiment in which the measured varaible has a range of values, for example, the independent variable might be a date and the dependent variable might be the highest temperature for that day.

When the dependent variable has a range of values, one records the values of the independent and dependent variables in a table. For example,

Date High Temperature (deg. C)
May 1, 2013 27
May 2, 2013 29
MaY 3, 2013 26

In your case the dependent variable has only two values, it worked or it didn't. Your table might look like

Alarm location Test Result (Worked or not)
Kitchen window Yes
Front door Yes
Basement window No

I hope this helps.

Your experiment is unusual because it doesn't measure anything about nature such as the high temperature. If a part of the alarm system doesn't work, does that tell you anything about the natural world such as how hot is the weather today? It might not work because somebody turned the power off, or a wire broke, or somebody didn't pay the alarm company bill. A better experiment for your next project would be to test something about the natural world. That is what scientists are supposed to do.

WW