Presentation on theme: "Understanding Variables… The variables collected were age, gender, income for 2011, and monthly spending on a variety of extra-curricular activities. a)"— Presentation transcript:
Understanding Variables… The variables collected were age, gender, income for 2011, and monthly spending on a variety of extra-curricular activities. a) What might have been the investigation about? b) Who might have been the population? c) Who might have been the sample?
By the end of the period… I can state the things the media does to misrepresent data.
Two Headlines from the Same Data Set Headline #1: EDSS Top School in Region, St. David Lowest in Waterloo (from 570News announcement, Sunday March 2, 2014) What is your initial reaction to this headline? Headline #2: Local schools score well in Fraser Institute’s annual rankings (from The Record, Monday March 3, 2014) What is your reaction to this headline, given what you read in headline #1?
The Data they were presented… Top schools in the Region according to Fraser Institute’s annual Ontario S.S. rankings (out of 740 schools): Elmira: Elmira District S.S. – 39 Guelph: Centennial – 48 Waterloo: Bluevale Collegiate – 103 Cambridge: Preston High School – 249 Kitchener: Grand River Collegiate – 273 Lowest ranking schools in the Region according to Fraser Institute’s annual Ontario S.S. rankings (out of 740 schools): Waterloo: St. David Catholic S.S. – 343 Cambridge: Glenview Park – 570 Kitchener: Eastwood Collegiate – 593 Guelph: College Heights – 724 Find out how your school fared here.here
The Record’s Article by Valerie Hill The Fraser Institute's annual School Report Card ranking system showed most schools in Waterloo Region are consistently scoring above average, although Guelph schools performed better at the elementary level. The report card was developed to gauge the academic success of individual schools. It is based on provincial tests administered by education ministries, focusing on math and literacy skills. The Ontario elementary school ranking system was launched in 2003, two years after it was implemented for secondary schools. It is based on a rating system from zero to 10, with the provincial average being six. The ranking identifies whether the school is performing above or below the provincial average and does not take into account all the other factors that make a school successful, such as skills learning or extracurricular activities. Sixteen Ontario elementary schools scored a ranking of 10 — including Guelph's Edward Johnson Public School, up from a previous ranking of 9.8. Fred A. Hamilton Public School in Guelph scored the next highest at 8.8. Three other Guelph elementary schools scored eight or higher. The highest ranking score in Waterloo Region elementary schools was Our Lady of Lourdes Catholic School in Waterloo, with a score of 8.7. It was followed by four schools with scores of 8.0: Lackner Woods Public School in Kitchener, Brigadoon Public School, Waterloo's French elementary school, L'Harmonié and Waterloo's French Catholic school, Mère-Élisabeth-Bruyère. Several schools in Kitchener and Waterloo scored between 7.0 and 7.9. The highest score for Cambridge schools was 7.3 for both St. Joseph Catholic School and Saginaw Public School. Two Cambridge schools received low rankings: Central Public School with 1.9, down from the previous year's score of 3.1 and St. Anne Catholic School with 0.6. The report did not include the school's previous year's scores. Also low ranked were Rockway Public School in Kitchener with 2.2, down from last year's 3.3 and in Cambridge, St. Peter Catholic School with a rank of 2.3, down from last year's 2.8. At the high school level, there were no schools in Ontario scoring a 10. The highest rank for a school in the region was Elmira District Secondary School, at 8.3, up from the previous year's 8.0. Bluevale Collegiate Institute came next with a rank of 7.7, down slightly from last year's 7.8. Schools that fell below average all ranked 5.7 and included Galt Collegiate, Jacob Hespler Secondary School and Kitchener Waterloo Collegiate and Vocational School. Scores were the same as the previous year, except for Kitchener Waterloo which increased from 5.6. Southwood Secondary School dropped to 5.6 from the previous year's score of 6.2. The lowest ranked high school in the region was Eastwood Collegiate Institute, at 4.8, down from the previous year's 4.9. For a full list and details on the rankings visit fraserinstitute.org.fraserinstitute.org. The Fraser Institute is an independent Canadian public policy research and educational organization.
The Media… The media are the major users of data. The media is used to inform the public of general issues. However, the media may sometimes provide misleading or false impressions to sway the public or to increase ratings/circulation.
Ways the media misrepresents data: Uses a catchy title Changes the scale on the axes Surveys a sample of the population that is too small Surveys a sample of the population that does not represent the population
How to avoid misrepresenting data: Use the most appropriate type of graph Use proper scales on the axes Ensure sample size is appropriate Ensure sample represents the population
Example #1 1. Based on the following graphs, which statement is true? A) The sale of cars is increasing faster than the sale of minivans B) There are more minivans sold than cars C) If the current trends continue, eventually there will be more minivans sold than cars D) The sale of minivans is increasing more slowly than the sale of cars
Example #2 Which statement is most accurate about the following graph? a. The temperature has increased dramatically in the last 100 years b. The graph makes the temperature increase seem less than it really is c. The temperature has increased slightly in the last 100 years d. The graph gives very little information
Example #3 The following graph may be misleading because the a. Vertical scale has a small range of values b. Type of coin is not specified c. Number of tosses is not specified d. Title is misleading
Example #4 Discuss how the results of the survey are misrepresented in this graph. A school is considering requiring students to wear school uniforms. A student takes a survey in the school and produces the following graph.
Example #5 Discuss why the following picture is misleading:
Additional Example These graphs have been created from the same data. What can you conclude from these graphs about the data?
Newspaper Headline: Traditional marriage on the decline: Census Canadian landscape shifts: Fewer of us are getting hitched, more of us are single and same-sex couples are tying the knot Actual article: http://cnews.canoe.ca/CNEWS/Politics/2012/09/19/20212311.html?cid=ETF 1. What impression does this give? 2. What additional information might you require?
In the slide that follows… 1. Critique the information provided using what you have learned today. Does the media present the information in a way that is not attempting to sway the reader? How does it help the reader understand the data? 2. What can you personally take away from the diagram? What things did you learn? What would you like more information on?
Taken from the 2011 Canadian Census with data provided by Stats Canada http://www.cnews.canoe.ca/CNEWS/Politics/2012/09/19/big-census.jpg