Data Mining Supplemental Resources on Class Website

Concept Map Data Mining Big Data Implementation Isolate Assumptions Design: Accuracy 3-D References Sum, Average, Min, Max, Count, RandBetween Paste Special Mixed Cell References

Objectives ▪ Explain the Accuracy principle of Spreadsheet Design ▪ Demonstrate Excel features that support basic data mining.

▪ Formula ▪ created by you ▪ = A1 + A10 ▪ Function ▪ keyword defined by Microsoft ▪ =SUM(A1:D1) ▪ Functions are more flexible than formulas Formula vs. Function

Different Results =B3+B4+B5+B6 =SUM(C3:C6) If you delete Row 5 =SUM(C3:C5)

▪ SUM ▪ AVERAGE ▪ MIN and MAX ▪ COUNT Common Functions

Cell AddressReferenceChanges when Copied A1RelativeVertically or Horizontally $A$1AbsoluteNever $A1MixedVertically A$1MixedHorizontally

Vertical Copy

Vertical vs. Horizontal Copy

▪ Is the formula entered going to be copied? ▪ If so, which direction? ▪ If it’s copied vertically, do you want the row references to change? If it’s copied horizontally, do you want the column references to change? ▪ Do you want such a change to take place? Cell Reference Decisions

1.Will you copy this function? 2.If so, which direction: vertical or horizontal? 3.If you copy vertically, Excel will automatically change all relative row references. Do you want those row references to change? Cell Reference Example #1 = SUM(B2:D2 )

Cell Reference Example #2 ▪ Which calculation needs a mixed cell reference? ▪ Where should the $ go?

▪ Know the order of operations. ▪ Select the correct function or construct the correct formula. (Choose a function over a formula.) ▪ Isolate assumptions. ▪ Check relative and absolute cell references. ▪ Double-check all calculations. Spreadsheet Design: Accuracy

▪ Store numbers in cells ▪ Write equations to point to cells containing numbers Isolate Assumptions

Isolate Assumption Example Assumption =E2+3 is incorrect =E2+H2 is correct

Generate Data with RANDBETWEEN ▪ = RANDBETWEEN(low, high)

Paste Special - Values MAC: Edit Menu, Paste Special

3-D Reference ▪ Cell reference that refers to a cell on a different worksheet ▪ Function is on Sheet 1 ▪ Summing cell A1 on Sheets 2 thru 13 =SUM(‘Sheet 2:Sheet 13’!A1)