From 8a7dfa0972c83fd811a4296e7373574bea4a28d0 Mon Sep 17 00:00:00 2001 From: Nguyễn Gia Phong Date: Sun, 19 Jul 2020 20:34:40 +0700 Subject: [usth/ICT2.7] Remove Udacity transcribes --- .../14 - Testing Introduction - lang_en_vs4.srt | 119 --------------------- 1 file changed, 119 deletions(-) delete mode 100644 usth/ICT2.7/P4L1 General Concepts Subtitles/14 - Testing Introduction - lang_en_vs4.srt (limited to 'usth/ICT2.7/P4L1 General Concepts Subtitles/14 - Testing Introduction - lang_en_vs4.srt') diff --git a/usth/ICT2.7/P4L1 General Concepts Subtitles/14 - Testing Introduction - lang_en_vs4.srt b/usth/ICT2.7/P4L1 General Concepts Subtitles/14 - Testing Introduction - lang_en_vs4.srt deleted file mode 100644 index 70df565..0000000 --- a/usth/ICT2.7/P4L1 General Concepts Subtitles/14 - Testing Introduction - lang_en_vs4.srt +++ /dev/null @@ -1,119 +0,0 @@ -1 -00:00:00,340 --> 00:00:02,290 -So let's talk more about testing, as we said a - -2 -00:00:02,290 --> 00:00:06,500 -little earlier in the lesson, testing means executing the program on - -3 -00:00:06,500 --> 00:00:09,400 -a sample of the input domain, that is of all - -4 -00:00:09,400 --> 00:00:12,210 -the possible input data and I really want to stress that - -5 -00:00:12,210 --> 00:00:16,190 -this sample is tiny sample of the input domain. There - -6 -00:00:16,190 --> 00:00:19,154 -are two important aspects of testing that I'm want to mention here, - -7 -00:00:19,154 --> 00:00:22,360 -there first one is that testing is a dynamic technique. And - -8 -00:00:22,360 --> 00:00:25,370 -what that means is that the program must be executed in - -9 -00:00:25,370 --> 00:00:28,130 -order to perform testing. The second important point is that - -10 -00:00:28,130 --> 00:00:32,040 -testing is an optimistic approximation. And what does it mean - -11 -00:00:32,040 --> 00:00:35,590 -to be optimistic? Well, it means that the program under - -12 -00:00:35,590 --> 00:00:38,820 -test is exercised with a very small subset of all the - -13 -00:00:38,820 --> 00:00:41,260 -possible inputs as we just said. And this is done - -14 -00:00:41,260 --> 00:00:45,150 -under the assumption that the behavior with any other input - -15 -00:00:45,150 --> 00:00:47,770 -is consistent with the behavior shown for the selected subset - -16 -00:00:47,770 --> 00:00:51,140 -of input data, that is why it is an optimistic approach. - -17 -00:00:51,140 --> 00:00:54,620 -Another concept that I want to mention explicitly, is the - -18 -00:00:54,620 --> 00:00:57,930 -concept of successful test. And I'm going to do that, - -19 -00:00:57,930 --> 00:01:01,260 -using another quote. This one from Goodenough and Gerhart - -20 -00:01:01,260 --> 00:01:03,850 -in their paper Towards a Theory of Test Data Selection, - -21 -00:01:03,850 --> 00:01:06,420 -and what the quote says is that a test - -22 -00:01:06,420 --> 00:01:10,000 -is successful if the program fails. And this might sound - -23 -00:01:10,000 --> 00:01:13,650 -counterintuitive, but the point here is that testing cannot - -24 -00:01:13,650 --> 00:01:16,490 -prove the absence of errors, but only reveal their presence. - -25 -00:01:16,490 --> 00:01:21,550 -If a set of tests does not produce any failure, we are either in the extremely - -26 -00:01:21,550 --> 00:01:24,050 -unlikely case of a correct program, or in - -27 -00:01:24,050 --> 00:01:26,650 -the very likely situation of a bad set of - -28 -00:01:26,650 --> 00:01:30,932 -tests that are not able to reveal failures of the program. And that is why we - -29 -00:01:30,932 --> 00:01:32,730 -say that the test is successful if you - -30 -00:01:32,730 --> 00:01:35,110 -can show that there are problems in the program. -- cgit 1.4.1