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
I see 3 columns of numbers. The first starts at 1 and appears to be an index. The second is a number with ~5 decimal places that appears to be a timed value, probably from the time I opened the program. The third colum is another number with ~5 decimal places, and appears to be the interval between the timer values in the second column.
Your TIMER data from 20 fast clicks
1 217.2266 217.2266
2 217.3984 .171875
3 217.5469 .1484375
4 217.6953 .1484375
5 217.8672 .171875
6 218.0313 .1640625
7 218.1875 .15625
8 218.2969 .109375
9 218.4609 .1640625
10 218.5938 .1328125
11 218.7578 .1640625
12 218.9297 .171875
13 219.1094 .1796875
14 219.25 .140625
15 219.4063 .15625
16 219.5625 .15625
17 219.7031 .140625
18 219.8516 .1484375
19 220.0078 .15625
20 220.1719 .1640625
21 220.3594 .1875
22 220.5234 .1640625
Your average time interval for 20 time intervals
0.147265
I took the ending value and subtracted the beginning value from it, giving me the length of time from first click to twentieth click. Then I divided that number by 20, which would give me 20 equal intervals. This would be the same as an average of the 20 intervals.
220.17190 - 217.2266= 2.9453
2.9453 / 20 = 0.147265
Your frequency distribution for the 20 time intervals (interval, number of times it was observed)
.171875, 3
.1484375, 3
.1640625, 4
.15625, 4
.109375, 1
.1328125, 1
.140625, 2
.1796875, 1
.1875, 1
Your general comment to this point
Comma Separated Values? I wonder if this is going to go into another program
This provides a uniform format for those experiments in which we might want to pool data from a number of different students.
Why did you observe only certain time intervals?
The TIMER program probably reported that time so frequently due to the resolution of the computer itself (or precision as the book might say). The clicks probably were coming in on times like .1830, but they were processed and stored at clock intervals such as .1875. Is the program flawed? No, it is recording the intervals as best it can within the constraints of the system it operates in. Is the program useless? No, it probably good down to 3 or 4 decimal places.
What did you see when you looked at the differences between time successive time intervals?
I see that the values are 1x and 2x the same interval, .01563. This tells us that the resolution (precision) of the TIMER program's smallest unit of measurement is .01563, and it cannot see any increment smaller than that.
Very good. Note that this is 1/64 second, the same as 4/256 second.
Actual reported times from different computers are always multiples of 1/256 second, and the smallest intervals between reported times are always 1/64 second.
Your time intervals for 7 complete breaths:
8.796875
10.625
12.95313
12.46094
15.09375
16.0625
17.07031
16.20313
18.72656
17.1875
Your general comment to this point:
Why did you rarely, if ever, observe that same time interval twice?
I would say we could expect this because we were not entering data (clicks) at intervals close to the smallest unit the TIMER could register.
That's a very good way to put it.
Do you think this program is accurate to .1 or .01 ...
I would say a., the TIMER program is capable of determining the time between two events accurately to within about .1 second.
I reason it this way: .01563 seems to be the smallest increment it can measure. If two events are .02 seconds apart, the TIMER cannot capture that...the interval will either be .01563 or .03125 seconds. The program should have no problem differentiating between events that take place .1 seconds.
Copy of a few lines of your spreadsheet from the TIMER program.
event number clock time time interval
1 5.29 5.29
2 5.49 0.2
3 5.71 0.22
4 5.94 0.23
5 6.17 0.23
It took me about 1 1/2 hours, but I also had to go and download the OCX file to make the timer program run.
Very good. We'll be reviewing this data as a group, but your conclusions agree with those I obtained with this experiment, and verified through a little more extensive programming investigation.