Exploratory testing: Difference between revisions

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{{Short description|Software testing approach}}

'''Exploratory testing''' is an approach to [[software testing]] that is concisely described as simultaneous learning, [[test design]] and test execution. [[Cem Kaner]], who coined the term in 1984,<ref>Cem Kaner, "[http://www.kaner.com/pdfs/QAIExploring.pdf A Tutorial in Exploratory Testing] {{Webarchive|url=https://web.archive.org/web/20130612043734/http://www.kaner.com/pdfs/QAIExploring.pdf |date=2013-06-12 }}", p.2</ref> defines exploratory testing as "a style of software testing that emphasizes the personal freedom and responsibility of the individual tester to continually optimize the quality of his/her work by treating test-related learning, test design, test execution, and test result interpretation as mutually supportive activities that run in parallel throughout the project."<ref>Cem Kaner, ''[http://www.kaner.com/pdfs/QAIExploring.pdf A Tutorial in Exploratory Testing] {{Webarchive|url=https://web.archive.org/web/20130612043734/http://www.kaner.com/pdfs/QAIExploring.pdf |date=2013-06-12 }}'', p. 36.</ref>

While the software is being tested, the tester learns things that together with experience and [[creativity]] generates new good tests to run. Exploratory testing is often thought of as a [[black box testing]] technique. Instead, those who have studied it consider it a test ''approach'' that can be applied to any test technique, at any stage in the development process. The key is not the test technique nor the item being tested or reviewed; the key is the cognitive engagement of the tester, and the tester's responsibility for managing his or her time.<ref>Cem Kaner, ''[http://www.kaner.com/pdfs/QAIExploring.pdf A Tutorial in Exploratory Testing] {{Webarchive|url=https://web.archive.org/web/20130612043734/http://www.kaner.com/pdfs/QAIExploring.pdf |date=2013-06-12 }}'', p. 37-39, 40- .</ref>

== History ==

Exploratory testing has always been performed by skilled testers. In the early 1990s, [[ad hoc]] was too often synonymous with sloppy and careless work. As a result, a group of test methodologists (now calling themselves the [[Software testing controversies|Context-Driven School]]) began using the term "exploratory" seeking to emphasize the dominant thought process involved in unscripted testing, and to begin to develop the practice into a teachable discipline. This new terminology was first published by [[Cem Kaner]] in his book ''Testing Computer Software'' <ref name=Kaner7-11>Cem Kaner, ''Testing Computer Software'', TAB Books, Blue Ridge Summit, PA, 1988. p. 6, 7-11.</ref> and expanded upon in ''Lessons Learned in Software Testing''.<ref>

{{cite book

|last = Kaner

|first = Cem

|authorlinkauthor-link = Cem Kaner |author2=Bach, James |author3=Pettichord, Bret

|title = Lessons Learned in Software Testing

|publisher = [[John Wiley & Sons]]

|year = 2001

|isbn = 978-0-471-08112-48}}

</ref><!--The entire book discusses techniques used in Exploratory testing. They can also be used in other types of testing.--> Exploratory testing can be as disciplined as any other intellectual activity.

== Description ==

Exploratory testing seeks to find out how the software actually works, and to ask questions about how it will handle difficult and easy cases. The quality of the testing is dependent on the tester's skill of inventing [[Test case (software)|test case]]s and finding [[software bug|defects]]. The more the tester knows about the product and different [[test method]]s, the better the testing will be.

To further explain, comparison can be made of freestyle exploratory testing to its antithesis [[test script|scripted testing]]. In the latter activity test cases are designed in advance. This includes both the individual steps and the expected results. These tests are later performed by a tester who compares the actual result with the expected. When performing exploratory testing, expectations are open. Some results may be predicted and expected; others may not. The tester configures, operates, observes, and evaluates the product and its behaviour, critically investigating the result, and reporting information that seems likely to be a bug (which threatens the value of the product to some person) or an issue (which threatens the quality of the testing effort).

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In reality, testing almost always is a combination of exploratory and scripted testing, but with a tendency towards either one, depending on context.

According to [[Cem Kaner]] &and [[James Marcus Bach]], exploratory testing is more a [[mindset]] or "...a way of thinking about testing" than a methodology.<ref>Cem Kaner, James Bach, ''Exploratory & Risk Based Testing'', [http://www.testingeducation.org/a/nature.pdf www.testingeducation.org] {{Webarchive|url=https://web.archive.org/web/20080511190045/http://testingeducation.org/a/nature.pdf |date=2008-05-11 }}, 2004, p. 10</ref> They also say that it crosses a continuum from slightly exploratory (slightly ambiguous or vaguely scripted testing) to highly exploratory (freestyle exploratory testing).<ref>Cem Kaner, James Bach, ''Exploratory & Risk Based Testing'', [http://www.testingeducation.org/a/nature.pdf www.testingeducation.org] {{Webarchive|url=https://web.archive.org/web/20080511190045/http://testingeducation.org/a/nature.pdf |date=2008-05-11 }}, 2004, p. 14</ref>

The documentation of exploratory testing ranges from documenting all tests performed to just documenting the [[software bug|bugs]]. During [[pair testing]], two persons create test cases together; one performs them, and the other documents.

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== Scientific studies ==

Replicated experiment has shown that while scripted and exploratory testing result in similar defect detection effectiveness (the total number of defects found) exploratory results in higher efficiency (the number of defects per time unit) as no effort is spent on perpre-designing the test cases.<ref>{{Cite journal|lastlast1=Itkonen|firstfirst1=Juha|last2=Mäntylä|first2=Mika V.|date=2013-07-11|title=Are test cases needed? Replicated comparison between exploratory and test-case-based software testing|url=http://link.springer.com/article/10.1007/s10664-013-9266-8|journal=Empirical Software Engineering|language=en|volume=19|issue=2|pages=303–342|doi=10.1007/s10664-013-9266-8|issn=1382-3256|citeseerx=10.1.1.363.6524|s2cid=254472881 }}</ref> Observational study on exploratory testers proposed that the use of knowledge about the ___domain, the system under test, and customers is an important factor explaining the effectiveness of exploratory testing.<ref>{{Cite journal|lastlast1=Itkonen|firstfirst1=J.|last2=Mäntylä|first2=M. V.|last3=Lassenius|first3=C.|date=2013-05-01|title=The Role of the Tester's Knowledge in Exploratory Software Testing|url=http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6298893|journal=IEEE Transactions on Software Engineering|volume=39|issue=5|pages=707–724|doi=10.1109/TSE.2012.55|s2cid=1763558 |issn=0098-5589}}</ref> A case-study of three companies found that ability to provide rapid feedback was a benefit of Exploratory Testing while managing test coverage was pointed as a short-coming.<ref>{{Cite journalbook|lastlast1=Itkonen|firstfirst1=J.|last2=Rautiainen|first2=K.|datetitle=2005-11-01 International Symposium on Empirical Software Engineering, 2005 |titlechapter=Exploratory testing: aA multiple case study |url=http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=1541817|journaldate=2005 International Symposium on Empirical Software Engineering, 2005.-11-01|pages=10 pp.–|doi=10.1109/ISESE.2005.1541817|isbn=978-0-7803-9507-7|s2cid=7974121 }}</ref> A survey found that Exploratory Testing is also used in critical domains and that Exploratory Testing approach is places high demands on the person performing the testing.<ref>{{Cite journalbook|lastlast1=Pfahl|firstfirst1=Dietmar|last2=Yin|first2=Huishi|last3=Mäntylä|first3=Mika V.|last4=Münch|first4=Jürgen|date=2014-01-01|title=How is Exploratory Testing Used? A State-of-the-practice Survey|url=http://doi.acm.org/10.1145/2652524.2652531|journal=Proceedings of the 8th ACM/IEEE International Symposium on Empirical Software Engineering and Measurement |chapter=How is exploratory testing used? A state-of-the-practice survey |date=2014-01-01|series=ESEM '14|___location=New York, NY, USA|publisher=ACM|pages=5:1–5:10|doi=10.1145/2652524.2652531|isbn=9781450327749|hdl=10138/153363|s2cid=17924562 }}</ref>

== Usage ==

Exploratory testing is particularly suitable if [[software requirement|requirements]] and [[Program specification|specifications]] are incomplete, or if there is lack of time.<ref name=Bach-ETE>{{Cite web

| last = Bach

| first = James

| title = Exploratory Testing Explained

| publisher = satisfice.com

| year = 2003

| page = 7

| url = http://www.satisfice.com/articles/et-article.pdf

| accessdate = October 23, 2010}}</ref><ref name=Kaner-TET>{{Cite web

| last = Kaner

| first = Cem

| title = A Tutorial in Exploratory Testing

| publisher = kaner.com

| year = 2008

| url = http://www.kaner.com/pdfs/QAIExploring.pdf

| pages = 37, 118

| accessdate = October 23, 2010}}</ref>

The approach can also be used to verify that previous testing has found the most important defects.<ref name=Bach-ETE />

== See also ==

{{portal|Software Testing}}

* [[Ad hoc testing]]

* [[Spike (software development)|Spike testing]]

== References ==

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== External links ==

* James Bach, ''[http://www.satisfice.com/articles/et-article.pdf Exploratory Testing Explained]''

* Cem Kaner, James Bach, ''[http://www.testingeducation.org/a/nature.pdf The Nature of Exploratory Testing] {{Webarchive|url=https://web.archive.org/web/20080511190045/http://testingeducation.org/a/nature.pdf |date=2008-05-11 }}'', 2004

* Cem Kaner, James Bach, ''[http://www.context-driven-testing.com The Seven Basic Principles of the Context-Driven School]''

* Jonathan Kohl, ''[http://www.methodsandtools.com/archive/archive.php?id=65 Exploratory Testing: Finding the Music of Software Investigation]'', Kohl Concepts Inc., 2007

* Chris Agruss, Bob Johnson, ''[http://www.testingcraft.com/ad_hoc_testing.pdf Ad Hoc Software Testing]''

{{portal|Software Testingtesting}}

{{DEFAULTSORT:Exploratory Testing}}