#$&*
Phy 241
Your 'timer program' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
#$&* Your General Comment **
#$&* Describe what you see on your first 10 clicks **
About 20 minutes.
#$&*Your TIMER data from 20 fast clicks **
Operating the TIMER program
It is easy to operate the Timer program. All you have to do is click on the button labeled Click to Time Event.
Click that button about 10 times and describe what you see.
There are two sets of numbers beside the number of the event. one is a larger number (759.3438) and the other is generally small. (.4609375) but is larger the longer you wait
between clicks.
#$&*
Now click on Initialize Counter, which will clear all the data from the timer window. Click the mouse as fast as you can until the TIMER window fills up. Be sure you get at
least 20 time intervals.
If you miss a click, try again. Keep trying until you get at least 20 intervals without a missed or delayed click.
Copy your data starting in the next line:
1 988.959 988.959
2 989.0332 7.421875E-02
3 989.1406 .1074219
4 989.2441 .1035156
5 989.3516 .1074219
6 989.4688 .1171875
7 989.5723 .1035156
8 989.6797 .1074219
9 989.7949 .1152344
10 989.9004 .1054688
11 990.0176 .1171875
12 990.1309 .1132813
13 990.25 .1191406
14 990.3672 .1171875
15 990.4883 .1210938
16 990.6035 .1152344
17 990.7188 .1152344
18 990.8301 .1113281
19 990.9492 .1191406
20 991.0547 .1054688
21 991.1777 .1230469
#$&*
You got at least 20 time intervals. Based on your data what was the average of the first 20 time intervals? Note that you could get this average by averaging the first 20
intervals. My first few intervals were .15625, .15625, .1875, .171875, etc; I could just add up the first 20 intervals and divide by 20 to get the average. However there is an
easier and quicker way to get the result, so use the easier way if you can.
Give your result, number only, in the first line, and starting in the second line explain how you got it.
0.1109375
I added them all together and divided by 20, but I did it by copying the data into excel and letting it do the averaging.
#$&*
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You could have subtracted two of the clock times and divided by the number of intervals.
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One subraction, one division, Excel is unnecessary but the process you describe would provide a good check.
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When I did this activity the first few lines of my data were as follows:
event number clock time time interval
1 11.67188 11.67188
2 11.875 0.203125
3 12.0625 0.1875
4 12.20313 0.140625
5 12.375 0.171875
6 12.54688 0.171875
7 12.73438 0.1875
8 12.92188 0.1875
9 13.10938 0.1875
10 13.28125 0.171875
11 13.4375 0.15625
It looks like the same intervals keep popping up. For example .1875 seconds occurs 5 times out of the first 10 intervals, .171875 seconds occurs three times, and .203125
seconds, .140625 seconds and .15625 seconds each occur once.
A frequency distribution for my time intervals would be as follows:
time interval frequency
,140625 1
.15625 1
.171875 3
.1875 5
.203125 1
What different time intervals did you observe in your first 20 intervals, and how many times did each occur? List below the different time intervals you observed and the
number of times each occurred. List from the shortest to the longest interval, and use a comma between the time interval and its frequency. For example my data above would be
listed at
.140625, 1
.1565, 1
.171875, 3
.1875, 5
.203125, 1
Your list should be in exactly this format, with no other symbols or characters.
.07421875, 1
.1035156, 2
.1054688, 2
.1074219, 3
.1113281, 1
.1132813, 1
.1152344, 3
.1171875, 3
.1191406, 2
.1210938, 1
.1230469, 1
#$&*
You may make any comments or ask any question about the process so far in the box below
???Is there an easier way to find the average?
#$&*
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See my previous note.
You can also find an average from a frequency distribution, which would be an appropriate use of Excel.
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On the 10 intervals I've shown you, do you really think I managed to get a time of .1875 seconds, accurate to 4 significant figures, on half of the intervals? If you do, I'm
grateful for your confidence but I'm just not that good. No human being has that much neurological and muscular control.
So why do you think the TIMER program reported that time so frequently? Why weren't there times like .1830 seconds, or .1769 seconds? Does this mean that the TIMER program is
flawed? Does that mean it's useless?
It appears that the second collumn is really just the ammount of time between the two clicks and not a running time interval. This does not mean it is uesless, it just makes
it more useful as is for measuring times between the individual events.
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The point of this question is the meaning of the fact that we get repeated time intervals on a 20-interval sample. What does this say about the accuracy and precision of the TIMER?
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Here are a few more lines of data, with an added column showing the difference between each time interval and the next.
clock time time interval difference from one time interval to next
9 13.10938 0.1875 -0.01563
10 13.28125 0.171875 -0.01563
11 13.4375 0.15625 0.03125
12 13.625 0.1875 -0.01563
13 13.79688 0.171875 0.015625
14 13.98438 0.1875 0.015625
15 14.1875 0.203125 -0.03125
16 14.35938 0.171875 -0.01563
17 14.51563 0.15625 0.03125
Take a good look at that last column and tell us what you see in those numbers, and what this tells you about the TIMER program
This seems to confirm my theory that the second collumn is the change between clicks and clock time. Since that interval may be shorter or longer, you can get get negative or
positive numbers from one interval to the next.
#$&*
Now initialize the TIMER once more, and take a series of 10 relaxed breaths. Every time you start to inhale, hit the TIMER button.
My results for the first 7 complete breaths are as follows:
series of relaxed breaths
event number clock time time interval difference between time interval and next
1 1569.734 1569.734
2 1582.75 13.01563 0.32812
3 1596.094 13.34375 3.90625
4 1613.344 17.25 2.70313
5 1633.297 19.95313 1.35937
6 1654.609 21.3125 4.23438
7 1680.156 25.54688 2.15625
8 1707.859 27.70313
I didn't go on because the time between my breaths kept increasing, and I was afraid if I relaxed any more I might stop breathing altogether. It's going to take either more
statistical analysis to determine whether that's a real danger, or a little common sense.
Report your results by just entering your time intervals, one to each line, in the box below. If I was entering my results I would enter
13.01563
13.34375
17.25
19.95313
21.3125
etc.
Enter your results in the same format:
4.902344
5.664063
5.453125
6.214844
6.332031
5.976563
6.285156
5.195313
5.800781
#$&*
If you have any comments please insert them here
#$&*
Most likely you did not observe the same exact time interval twice, and if you did it did not happen nearly as often as when you did the fact clicks.
Why do you think this is exactly what we would expect?
Since this is a longer event there is less chance that the interval will be exact since it is measuring to a very precise time.
#$&*
Which of the following statements do you think is the most accurate?
a. The TIMER program is capable of determining the time between two events accurately to within about .1 second.
b. The TIMER program is capable of determining the time between two events accurately to within about .01 second.
c. The TIMER program is capable of determining the time between two events accurately to within about .001 second.
d. The TIMER program is capable of determining the time between two events accurately to within about .0001 second.
Enter your answer and your reasoning below:
I would say C, because while the intervals may have more figures, the actual clock time only goes out to .001 seconds. This means that any numbers past that would only be
estimates.
#$&*
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Is your conclusion consistent with the observed frequency of repeated intervals?
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Note that the TIMER.exe program can save your data in a format that can be read by a spreadsheet (the TIMER applet cannot do so). This will be very handy in the future, so
take a minute and do the following:
1. Click on the button at the lower right of the TIMER form, entitled Click to File Data.
2. A box will pop up allowing you to include an identifying message. You should generally choose to include such a message; for the data presently on your timer that might be
'series of regular breaths time at beginning of inhalation' or something similar. Type in whatever you think would serve as a good identifier for this data and OK that box.
3. A typical Save As window will appear. Decide where to save your data and what to call it, and proceed to save it. The program will save the file as a comma-delimited text
file.
4. Open your spreadsheet program (typically Excel) and choose File > Open. Browse to the folder in which you just saved your data. Below the File Name line will be a File Type
line; set this either to Text Files or All Files so your file will appear. Open it.
5. A series of windows will typically appear. In the first window make sure the file type chosen is Delimited, the proceed to the next window.
6. In the second window you will see a series of checkboxes; check the one entitled Comma, in order to select the comma-delimited file, then just click on Finish.
If you can't run the .exe program, you can't do Steps 1-3. However all you need to do is copy the contents of the program to a text file, using copy-and-paste. Save that text
file, using any filename you wish. Then proceed with steps 4-6 above.
Your data should appear in your spreadsheet, and can be manipulated as in any spreadsheet.
Copy a few lines of the data from your spreadsheet below:
Breath Times
event number clock time time interval
1 2561.785 2561.785
2 2566.688 4.902344
3 2572.352 5.664063
4 2577.805 5.453125
#$&*
*#&!
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Good work, but a couple of questions can be answered more specifically.
&#Please see my notes and, unless my notes indicate that revision is optional, submit a copy of this document with revisions and/or questions, and mark your insertions with &&&& (please mark each insertion at the beginning and at the end).
Be sure to include the entire document, including my notes.
If my notes indicate that revision is optional, use your own judgement as to whether a revision will benefit you. &#
*@