about summary refs log tree commit diff
path: root/usth/ICT2.7/P4L2 Black-Box Testing Subtitles/11 - Why Not Random Testing? - lang_en_vs4.srt
diff options
context:
space:
mode:
Diffstat (limited to 'usth/ICT2.7/P4L2 Black-Box Testing Subtitles/11 - Why Not Random Testing? - lang_en_vs4.srt')
-rw-r--r--usth/ICT2.7/P4L2 Black-Box Testing Subtitles/11 - Why Not Random Testing? - lang_en_vs4.srt143
1 files changed, 143 insertions, 0 deletions
diff --git a/usth/ICT2.7/P4L2 Black-Box Testing Subtitles/11 - Why Not Random Testing? - lang_en_vs4.srt b/usth/ICT2.7/P4L2 Black-Box Testing Subtitles/11 - Why Not Random Testing? - lang_en_vs4.srt
new file mode 100644
index 0000000..a91af45
--- /dev/null
+++ b/usth/ICT2.7/P4L2 Black-Box Testing Subtitles/11 - Why Not Random Testing? - lang_en_vs4.srt
@@ -0,0 +1,143 @@
+1

+00:00:00,310 --> 00:00:02,250

+So then maybe what we can do is just to

+

+2

+00:00:02,250 --> 00:00:05,720

+pick our test inputs randomly so to do what is called

+

+3

+00:00:05,720 --> 00:00:08,850

+random testing. And what that means is that we pick the

+

+4

+00:00:08,850 --> 00:00:11,720

+inputs to test just as we pick a number by rolling

+

+5

+00:00:11,720 --> 00:00:15,410

+a set of dice randomly. And this will have several advantages.

+

+6

+00:00:15,410 --> 00:00:18,780

+First, we will pick inputs uniformly. So if we use a

+

+7

+00:00:18,780 --> 00:00:21,790

+uniform distribution as the basis for our random testing, we will

+

+8

+00:00:21,790 --> 00:00:25,540

+make no preferences. In other words, all inputs will be considered

+

+9

+00:00:25,540 --> 00:00:28,324

+equal, of equal value. And what that means in turn, is

+

+10

+00:00:28,324 --> 00:00:32,640

+that random testing eliminates designer bias. So what does designer bias

+

+11

+00:00:32,640 --> 00:00:36,030

+mean? Designer bias is the problem of making the same assumption,

+

+12

+00:00:36,030 --> 00:00:38,570

+when we read the specification and we interpret it and when we

+

+13

+00:00:38,570 --> 00:00:42,100

+develop test cases. Which means that the developer might develop code,

+

+14

+00:00:42,100 --> 00:00:44,930

+assuming a given behavior of the user. And we may write

+

+15

+00:00:44,930 --> 00:00:47,520

+tests, making the same assumptions. And the problem, of course, is

+

+16

+00:00:47,520 --> 00:00:50,690

+even worse if it's the same person that develops the code and

+

+17

+00:00:50,690 --> 00:00:53,730

+writes the test cases. With random testing, the problem is gone,

+

+18

+00:00:53,730 --> 00:00:57,440

+because we just pick randomly what our inputs will be. So

+

+19

+00:00:57,440 --> 00:01:00,180

+why not do in random? The problem is that when testing,

+

+20

+00:01:00,180 --> 00:01:03,610

+we are looking for a needle in a haystack. Actually, multiple

+

+21

+00:01:03,610 --> 00:01:06,620

+needles in multiple haystacks, if we want to be precise. So,

+

+22

+00:01:06,620 --> 00:01:09,500

+random approaches are not necessarily the best way to go about

+

+23

+00:01:09,500 --> 00:01:12,430

+it, because we might just be looking in all the wrong

+

+24

+00:01:12,430 --> 00:01:15,760

+places. So let me show you this, using a different representation

+

+25

+00:01:15,760 --> 00:01:18,000

+for the haystack. What I'm showing here is a grid, and

+

+26

+00:01:18,000 --> 00:01:22,130

+imagine this grid just expanding indefinitely outside the screen, and this grid

+

+27

+00:01:22,130 --> 00:01:26,120

+represents the domain for the program, so each box in the grid,

+

+28

+00:01:26,120 --> 00:01:29,050

+each square in the grid, it's a possible input. So what happens

+

+29

+00:01:29,050 --> 00:01:32,670

+with bugs is that bugs are very scarce in this grid. Maybe

+

+30

+00:01:32,670 --> 00:01:35,070

+there is a bug here, so that means that there is a

+

+31

+00:01:35,070 --> 00:01:38,090

+bug, than an input, in this point we'll reveal. And maybe there

+

+32

+00:01:38,090 --> 00:01:40,820

+is another bug that will be triggered by an input over here.

+

+33

+00:01:40,820 --> 00:01:44,570

+So imagine this spread out over this infinite grid. Its very unlikely

+

+34

+00:01:44,570 --> 00:01:47,440

+that just by picking randomly that we will be able to get to

+

+35

+00:01:47,440 --> 00:01:50,910

+these two points. Fortunately not all is lost, there is a silver lining.

+

+36

+00:01:50,910 --> 00:01:53,410

+So we need to look a little more in depth into this grid.