One of the things which most of the Testers (me inclusive, many a times I have also not realized the importance of doing follow-up testing) don’t do when they get an error is - to do follow up testing. This mostly reduces the value of the Bug that you are reporting. The reason is you still have not identified the Bug in its worst form or not investigated the potential of that Bug. This would sometimes make the developers to defer the bug you have reported and the Bug may take its worst form in the field.
If a Tester wants the Bug reported by him to be fixed by the developer , then ensuring that he has investigated the Bug and reporting that Bug in its worst form, goes a long way in getting this done.
I was testing a text field in a web application which was not supposed to accept more than 1000 characters. I generated 1010 chars using PerlClip and pasted on this field. It just accepted 1000 characters and rejected the remaining 10 characters. I again tried appending more characters to the existing 1000 characters by trying to paste more characters, but it was also rejected. So I tried appending by giving keyboard input beyond 1000 characters and to my surprise the characters were getting appended. At this point, I could had logged a Bug saying that I am able to input more than 1000 characters to the text field which is an issue as per requirements. But I decided to do some follow up tests and tried to input as many characters as possible. I found that the field was allowing only 1000 characters to be pasted at a time, but if you give some keyboard input then again you can paste 1000 characters. So using this method I gave inputs of around 3 lakh characters. Then when I did further operation with the application where this data in the field had to be retained across couple of pages, the application initially slowed down when passing this data to the first page and then by the second page the application hung for around for 10mins before recovering.
Here if I had reported the Bug for the first error that I encountered i.e. “the text field accepting more than 1000 characters as input”, the severity of this Bug could not have been captured. But my follow-up test results, where I was able to input around 3 lakh characters to the text field and upon doing further operations the web application getting hanged showed the Bug in a more severe form. So the Bug report for the second case is more likely to catch the attention of the developer and has a better probability of getting fixed. The follow-up tests are sometimes simple and helps Testers in coming up with more credible and persuasive Bug Reports.