| How quickly or
slowly you react is called your reaction time. Your reaction time can be
measured by how long it takes for your eyes to tell your brain that an
object is falling and then for your brain to tell your fingers to catch
it. The falling object is called a stimulus and this type of reaction is
called a simple reaction. The simple reaction time is the time it
takes to react to a simple stimuli - or small change in the environment
(Wikipedia contributors, 2006).
In this experiment, reaction time is
measured by catching either a centimetre ruler or a reaction timer
(marked in fractions of a second) with your fingers. After you catch the
ruler, you record either the distance the ruler has dropped in
centimetres or the time indicated on the scale of the reaction timer. To
see if practice leads to improvement in reaction time, you will record
three attempts by several people - if the second and third attempts are
consistently quicker than the first, then this indicates that practice
may lead to improvement.
The spreadsheet shown above displays and
analyses the data in a number of ways, to help in answering the
question.
- It uses a chart to show first,
second and third attempts graphically - making it easier to compare
the three "tries";
- It uses a formula to calculate the
average reaction time for each person who has undertaken the test
(column E);
- It display these average times in a
bar chart, so that the people with fastest and slowest reactions can
be easily identified;
- It uses a formula to calculate the
totals for each of the three tries - again making it easier to
compare the attempts.
The purpose of creating this spreadsheet,
using MS Excel, is to illustrate ways in which a spreadsheet can
display and analyse data in different ways. It may be used in school,
but that is not its primary purpose - the intention is to give practice
in creating charts and entering formulae, so that you might use these
skills to create your own spreadsheet templates.
To create a spreadsheet similar to the
one above, follow these steps:
- Enter the text "Name" into cell A1
followed by 1st Try, 2nd Try, 3rd Try into cells B1, C1 and D1.
Enter the text "Average" into cell E1.
- List at least ten people (to make a
reasonably valid survey) into cells A2 to A11.
- To find the average of the three
tries at catching the reaction timer/ruler, enter the following
formula into cell E2: =AVERAGE(B2:D2) and press RETURN.
-
Copy the formula to cells E3 to E11 by dragging the
fill
handle
from cell E2 down to E11.
- To find the totals for the three
"tries". enter the following formula into cell B12: =SUM(B2:B11)
and use the fill handle to copy the formula to cells C12 and
D12. Note that, as with the AVERAGE formula in E2, the formula is
modified in each cell to refer to the appropriate column or row.
- Now using a ruler or reaction timer,
carry out your three reaction tests on your sample of ten people and
enter their times (as either centimetres dropped or decimal
fractions of a second) into the cells from B2 down to D11. Note that
the formulae in column E, will automatically calculate the average
reaction times as you proceed.
- To keep the average times relatively
simple, select cells E2 to E11 and select Cells... from the
Format menu. In the Number tab, set the Decimal
places to 1.
- To display the "tries" in a chart,
highlight the cells B2 to D11 and select the Chart Wizard
in the toolbar.
- In first window of the Wizard,
select a clustered horizontal bar chart and click the Next
button. In the Data Range window, select rows, not
columns and click the Next button.
- In the Legend tab of the next
window, uncheck the Show legend checkbox.
- In the Titles tab, give the
chart a title and label the X axis Tries and the Y axis
either cm dropped or seconds. Click Finish.
- Us the mouse pointer to resize the
chart and place it to the right of the table, next to column E.
- To create a chart showing average
times, select cells A1 to A11 and then, holding down the CONTROL
(Ctrl) button on the keyboard, select cells E1 to E11 - thsi
allows non-adjacent columns to be selected.
- In first window of the Wizard,
select a clustered column with 3-D visual effect chart and
click the Next button. In the Data Range window,
select columns, not rows and click the Next button. In the
Legend tab of the next window, uncheck the Show legend
checkbox.
- In the Titles tab, give the
chart a title and label the X axis Names and the Z axis
either cm dropped or seconds. Click Finish.
- Us the mouse pointer to resize the
chart and place it below the table.
- To complete the spreadsheet, fill
the unused background cells with a Fill colour, insert clip art and
add a Text Box for recording your interpretation of the data.
Detailed guidance is also available in
this MS Word document - reaction
times guide.doc
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