CRUNCHING NUMBERS

INDEX - MODULE 1 - MODULE 2 - MODULE 3
MODULE 4 - MODULE 5 - MODULE 6

MODULE One

Why build a database?

1) Why do we build databases? We gather data together in databases in order to explore questions. Do poor children have trouble in school? Can lunch programs make a difference? Can more money for teacher salaries help improve student performance? We may be looking for a relationship. Is there a connection between poverty and crime? Between poverty and the drop out rate? Do young people who finish high school have better lives? 2) Who needs databases? Leaders need data to see what works and how things are going. How many new jobs did we create? Groups need data to plan spending and programs. Which town has the greatest need? Private citizens need data to make smart decisions. What is my daughter's temperature after taking medicine? Collecting data about people in California or Mississippi is like taking the state's temperature. Political leaders need poll data to see how voters are thinking. School superintendents need data to keep track of student performance. Police commissioners need data to measure the effectiveness of various crime prevention programs. Car dealers may need a database to keep track of inventory. Homeowners may need a database to keep track of a CD collection. 3) What do databases look like? They are something like a bead tray . . . They help us to collect and store information into "fields" which are a bit like the pockets in the trays. Datasets are collections of numbers in columns (up and down) 5 5 5 5 5 5 and rows (across). 5 5 5 5 5 5 5 5 5 5 The table below is a dataset. It is a collection of numbers in rows and columns. 1985 1995 1985 1995 Kentucky 7 11.2 7.6 7.6 Louisiana 8.7 11.9 9.7 9.8 Mississippi 8.8 13.7 9.8 10.5 We can place the dataset information in a database if we want to sort and sift it. Later we may move it to a spreadsheet to do calculations. When we add field names and record names to a dataset, we change it into a database. In the example below, the words across the top row are the fields. The words listed down the side (states) are the individual records. Field Names State % Low Birth Weight 1985 Infant Mortality 1985 % Low Birth Weight 1995 Infant Mortality 1995 Kentucky 7 11.2 7.6 7.6 Louisiana 8.7 11.9 9.7 9.8 Mississippi 8.8 13.7 9.8 10.5 Take time to note how a database file is set up. It is different from a spreadsheet. A database file is comprised of "records" - each one of which is an entry with several "fields" telling about the record. In this case, each record is an American state. The fields contain important numbers about each state. Each field tells us some aspect of child well being. It may be the drop out rate or the infant mortality rate, for example. Later, when you work with the database program you will be able to sort the information. Each time the name of the state moves, all the other information associated with that state moves with it. In a spreadsheet, moving information in one column may not move the rest.   Open your word processor. Write brief explanations for each of the following: dataset database spreadsheet row column record field What can we learn about the lives of children in the three states from the information listed above? In your word processor list 3-4 statements you can make about children based on the numbers. Be prepared to defend and explain your findings. When you are done, please call your workshop leader over to see your ideas.   Please do not move ahead to the next activity until asked to do so by your workshop leader.

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