CS 103 Day 2, Wed. March 28, 2001 No Class Friday: 11:00 Memorial, Prof. Russ

• Note the numbers themselves make a kind of bar-graph shape (186 is small/short, 22,925 is large/long.)
• You find an average (pp.23-24) monthly attendance at the Exit Glacier site.  Is this a good summary for data for this variable?

• Continue with Chapter 1:  See notes, Day 1
• In Asst. 1, watch out for what I want printed!  Two copies of the graph, with the gridlines showing/not showing. Help..

• Data types:  Variables can be--
• Qualitative (Categorical)
• Nominal (names)
• Ordinal (order-able)
• Quantitative (numbers--it makes sense to average them...)
• Format for data set:   A Row is a Record (a Case, an individual). A Column is a Variable.
• It's good to have a unique I.D. (Case) number too

ID	Name	Height	Chocolate feelings	Housenumber	Number of cats
101	Ann	68	Love	1235	3
102	Mary	62	Hate	406	1
103	Mary	65	Like	825	0

• Sorting and filtering are powerful tools for picking out cases (best, worst, above a cutoff...)  They will only work on alphabetical or numerical values. (So Chocolate feelings should be "coded" into numbers)

• p. 34 top:  Fill handle is nifty, useful.
• p.34 bottom-35: the Enter-data-using-a-range method is overly fancy, and also creaky.  Get the numbers in somehow. (Use arrow keys.)
• p. 37-38:  Range names are useful.  They CANNOT have spaces; Excel will substitute underline_ for a space if you make the name from a column header containing a space.  Then when you use it you will have to know it is different from the column header.
• p. 39 Cell references, relative B5, or absolute $B$5, or mixed $B5,  B$5.  Important concept when making and reusing formulas. Not in text: The F4 key will put the$ in.  In-class demonstration.
• pp.39-40 Inserting a row.  One of the most common sources of subtle error in spreadsheet design is inserting a row at the end of a range, thinking it has gone into the formulas using that range, when it hasn't!
• p.41 Sorting:  Excel assumes you want to sort the whole block of data (surrounded by empty cells). Check its range choice.  If you don't like its selection, you can select a range ahead of choosing the Sort option.
• p. 43 Filtering:  <= has been replaced by words "is less than or equal to"
• p. 46ff.  "Optional"--some people have made this work; others haven't.  Don't fret over it.