How to Make a Valid and Unbiased Survey

First Step Brainstorm… What is the topic of your survey What is the objective, or what information are you trying to obtain Make sure your questions specifically address the objectives you are trying to learn, for ex: If you are trying to make a survey on drug usage for high school students, you might ask, “Have you ever tried Marijuana?” and if so, “How often do you smoke marijuana?”

Who is the audience? If you are going to ask a small group you can ask everybody (called a Census) If you want to survey a large group, you may not be able to ask everybody so you should ask a sample of the population (this is called Sampling)

What does bias have to do with it? If you are Sampling you should be careful who you ask, for example: If you only ask people who look friendly, you will only know what friendly people think! If you went to the swimming pool and asked people "Can you swim?" you will get a biased answer ... maybe even 100% will say "Yes" The surveys where people are asked to ring a number to vote are not very accurate, because only certain types of people actually ring up! So be careful not to bias your survey. Example: You want to know the favorite colors for people at your school, but don't have the time to ask everyone. Solution: Choose 50 people at random: stand at the gate and choose "the next person to arrive" each time or choose people randomly from a list and then go and find them! or you could choose every 5th person Your results will hopefully be nearly as good as if you asked everyone.

Now that you have your audience, Create the survey… Types of Questions A survey question can be: Open-ended (the person can answer in any way they want), or Closed-ended (the person chooses from one of several options) Closed ended questions are much easier to total up later on, but may stop people giving an answer they really want. Example: "What is your favorite color?" Open-ended: Someone may answer "dark fuchsia", in which case you will need to have a category "dark fuchsia" in your results. Closed-ended: With a choice of only 12 colors your work will be easier, but they may not be able to pick their exact favorite color.

Question Sequence It is important that the questions don't "lead" people to the answer Example: people may say "yes" to donate money if you ask the questions this way Do you love nature? Will you donate money to help the river? But probably will say "no" if you ask the questions this way: Is lack of money a problem for you? Will you donate money to help the river? To avoid this kind of thing, try to have your questions go: from the least sensitive to the most sensitive from the more general to the more specific from questions about facts to questions about opinions Go through your questions and put them in the best sequence possible Example: I will ask people how often they visit the river (a fact) before I ask them what they feel about pollution (an opinion) I will ask people their general feelings about the environment before I ask them their feelings about the river.

Make your questions Neutral Your questions should also be neutral ... allowing the person to think their own thoughts about the question. In the example before I had the question "Do you love nature?" ... that is a bad question because it is almost forcing the person to say "Yes, of course." Try rewording it to be more neutral, for example: Example: "How important is the natural environment to you?" Not Important Some Importance Very Important

Tally up the data or the results…. Tally the Results Now you have finished asking questions it is time to tally the results. By "tally" I mean add up. This usually involves lots of paperwork and computer work (spreadsheets are useful!) Example: For "favorite colors of my class" you can simply write tally marks like this (every fifth mark crosses the previous 4 marks, so you can easily see groups of 5):

The Results…. Look at your survey results for trends and patterns. What conclusions can you draw from the survey results? Write a conclusion, and include any tables or graphs that help you present your survey results

Ways to present your results Tables Sometimes, you can simply report the information in a table.  A table is a very simple way to show others the results.  A table should have a title, so those looking at it understand what it shows: Statistics You can also summarize the results using statistics, such as mean or standard deviation Example: you have lots of information about how long it takes people to get to school but it may be simpler just to present a summary such as: Shortest Journey: 3 minutes Average Journey: 22 minutes Longest Journey: 58 minutes

Graphs Nothing makes a report look better than a nice graph or chart There are many different types of graphs.  Three of the most common are: Line Graph  - Used to show information that is somehow connected (such as change over time) Pie Chart - Used most often to show survey data that is to be reported in percentages.  

People's Comments If people have given their opinions or comments in the survey, you can present the more interesting ones: Example: In response to the question "How can we best clean up the river?" we received these interesting replies: "The government has a special fund for this" "The local gardening group has seedlings you could plant"

Resources http://www.microsoft.com/education/DesignSurvey.aspx?pf=true http://www.mathsisfun.com/data/survey-conducting.html