#$&*
Phy 232
Your 'timer program' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** TIMER program_labelMessages **
5/20
12:00 am
** **
45 minutes
** **
It is easy to operate the Timer program. All you have to do is click on the button labeled Click to Time Event.
Click that button about 10 times and describe what you see.
There are three columns and the first column is the number of the run, the second is the time clicked, and the third is how many seconds apart the clicks are (it seems).
#$&*
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 62.75781 62.75781
2 62.90625 .1484375
3 63.07031 .1640625
4 63.23438 .1640625
5 63.39844 .1640625
6 63.75 .3515625
7 63.90625 .15625
8 64.07031 .1640625
9 64.25 .1796875
10 64.42188 .171875
11 64.625 .203125
12 64.78125 .15625
13 64.96094 .1796875
14 65.14844 .1875
15 65.32813 .1796875
16 65.5 .171875
17 65.6875 .1875
18 65.85938 .171875
19 66.03906 .1796875
20 66.23438 .1953125
21 66.39063 .15625
#$&*
You got at least 20 time intervals. Based on your data what was the average of the first 20 time intervals? Note that you could get this average by averaging the first 20 intervals. My first few intervals were .15625, .15625, .1875, .171875, etc; I could just add up the first 20 intervals and divide by 20 to get the average. However there is an easier and quicker way to get the result, so use the easier way if you can.
Give your result, number only, in the first line, and starting in the second line explain how you got it.
.16329
I added them all up and divided by twenty.
#$&*
@&
Good.
You could also have subtracted clock time 2 from clock time 21 and divided by 20. Be sure you understand why this would give you the same result. If you don't, ask.
*@
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.
.1484375, 1
.15625, 3
.1640625, 4
.171875, 3
.1796875, 4
.1875, 2
.1953125, 1
.203125, 1
.3515625, 1
@&
This last interval pretty clearly corresponds to a missed click. This means that your data set is slightly flawed--it doesn't quite correspond to 20 quick-click intervals.
*@
#$&*
You may make any comments or ask any question about the process so far in the box below
--
#$&*
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 seems that the timer rounds to the nearest calculable time interval. So if three times are very close to .1875, then it lists them as .1875.
#$&*
Here are a few more lines of data, with an added column showing the difference between each time interval and the next.
clock time
time interval
difference from one time interval to next
9
13.10938
0.1875
-0.01563
10
13.28125
0.171875
-0.01563
11
13.4375
0.15625
0.03125
12
13.625
0.1875
-0.01563
13
13.79688
0.171875
0.015625
14
13.98438
0.1875
0.015625
15
14.1875
0.203125
-0.03125
16
14.35938
0.171875
-0.01563
17
14.51563
0.15625
0.03125
Take a good look at that last column and tell us what you see in those numbers, and what this tells you about the TIMER program
It tells us that the timer program rounds to give the closest difference it can calculate.
#$&*
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:
3.476563
3 2.703125
3.140625
2.671875
3.109375
3.90625
3.179688
3.335938
2.164063
3.2343755
#$&*
If you have any comments please insert them here
--
#$&*
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 fast clicks.
Why do you think this is exactly what we would expect?
I think this is because breathing is more irregular and your clicks were based on perception of when you inhaled, so it was more likely the times would differ.
@&
Could the longer intervals have anything to do with this phenomenon?
*@
#$&*
Which of the following statements do you think is the most accurate?
a. The TIMER program is capable of determining the time between two events accurately to within about .1 second.
b. The TIMER program is capable of determining the time between two events accurately to within about .01 second.
c. The TIMER program is capable of determining the time between two events accurately to within about .001 second.
d. The TIMER program is capable of determining the time between two events accurately to within about .0001 second.
Enter your answer and your reasoning below:
C because the timer program has many decimal places but it seems to round off some of them and usually it's the third decimal place that differs.
@&
You observed only 8 intervals spanning time intervals from about .15 second to about .20 second.
If the TIMER was accurate to within .001 second, how many different possible results would there be between .15 second and .20 second, and what would be the chance that of these intervals, you would observe only 8 of them in 20 trials?
Does this change your conclusion or confirm it? If it changes your conclusion, what is your new conclusion?
*@
#$&*
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:
1 1351.953 1351.953
2 1355.43 3.476563
3 1358.133 2.703125
#$&*
*#&!
@&
Good overall, but check my notes.
I have asked two direct questions in my notes. My questions are very relevant to the question of the nature and reliability of our data.
I'll ask you to submit a revision in which you answer those questions.
&#Please see my notes and submit a copy of this document with revisions, comments 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. &#
*@