Home > Articles > Software Development & Management

Using Heuristic Test Oracles

  • Print
  • + Share This
When you see something that bugs you about an application, can you easily convince someone else that the defect really is a problem? Michael Kelly teaches a quick lesson in expressing yourself persuasively with a HICCUPP.
Like this article? We recommend

Quick! Test the application in Figure 1! No really, test it. It’s Google Earth (Beta version 3.0.0762). It’s okay, I’ll wait for you. Just don’t take more than an hour. I’ve got other people to share this example with.

Figure 1

Figure 1 Very cool Google software.

How did you do? Did you find any bugs? I found the little beauty in Figure 2just a couple of minutes into my testing. It seems that if you search with large strings, Google Earth thinks it has a network error. What’s even more interesting is that it actually changes your search criteria. I found that if I searched with a 5,000-character counterstring followed by a 1,000-character counterstring, Google Earth changed my search criteria back to the 5,000-character counterstring. It continued to do this for several different values.

Figure 2

Figure 2 Searching with large strings led to this error message.

Is this a good bug? Probably not—there’s a low likelihood that someone will actually have a valid reason to search with 5,000 characters. Is this a bug that should be fixed? Eventually—most likely there are more important bugs to fix (like the funny white lines when rendering). However, bugs like this are like blood in the water. They tell me that the developer may not have the control over the application that he thinks he has.

What does all this have to do with heuristic test oracles? Suppose you ask me, "How do you know the behavior you found above is a bug? You don’t have any requirements telling you what the software should do." To that, I might answer, "Uh, well...it just didn’t seem right to me." But that response wouldn’t win many supporters, would it?

Instead, I need to say something like, "I believe it’s a bug because the message states that there’s a network problem, and yet searches with smaller values still work. The search feature behaves inconsistently given the same network conditions. In addition, the search field changes my search text after I get the error message, but it doesn’t do that before I get the error message. That’s also inconsistent behavior. Finally, I truly don’t believe that there’s a network error, which means that Google Earth is reporting an inaccurate error message. I don’t believe Google really wants to report inaccurate error messages. That makes them look bad. That’s not good for their company image."

The rest of this article is intended to help you develop a vocabulary for explaining why you feel that something you find that looks wrong is in fact a bug. Rather than being forced to rely solely on incomplete requirements ("Where’s the requirement that says we should spell everything correctly?") or having to put your reputation on the line ("I think it’s a bug, and you should fix it because I’m a good tester"), this article offers some simple heuristic test oracles you can use to explain why you think something is a problem.

Enter the HICCUPP Heuristic

Last year, while I was working with James Bach, he had me test some small applications. When I would find a problem, James would ask me to explain why I thought that what I found was a problem. I quickly discovered that I had no vocabulary for why I thought that something was a problem. There were no requirements documents around, so I couldn’t point to something and say, "Look there. It’s a problem because that says so!" Instead, I just looked at him and said, "Well, it seems like it should work like this, not like that."

Obviously, that wasn’t good enough. James is fairly good at role playing, and I quickly got everything from a defensive developer ("Well, I don’t care if you’re a good tester—I’m a good developer, so it’s not a bug!") to a dismissive project manager ("Well, that’s just your opinion"). It seems that most people don’t react well when they suspect you’re being subjective.

James gave me the following handy mnemonic for test oracles (the principle or mechanism by which we recognize a problem): HICCUPP. Here’s what the letters stand for:

  • History
  • Image
  • Comparable Product
  • Claims
  • User Expectation
  • Product
  • Purpose

Let’s consider how you address these oracles:

  • Inconsistent with History. A product should be consistent with past versions (or history). History can include previous versions, patches, claims, etc. If something has changed, and no one told you it was supposed to change, then you might have found a problem.
  • Inconsistent with Image. Most companies want to have a good image in the marketplace. Therefore, their software needs to look professional and be consistent with accepted standards. If a product is inconsistent with the desired image, what you’re saying is this: "We’ll look silly (or unprofessional) if we release this software to market."
  • Inconsistent with Comparable Product. You’re letting another product serve as your oracle for this test. As long as the comparable product really is comparable, and you want your product to be an alternative to that product, or you want to get the users that that product has, then this oracle can be very compelling.
  • Inconsistent with Claims. A "claim" can be anything that someone in your company says about the product. If something is inconsistent with claims, it’s inconsistent with the product’s stated requirements, help, marketing material, or just something that a project stakeholder said in the hallway.
  • Inconsistent with User Expectations. This product doesn’t do something that a reasonable user of this product would expect it to do, or doesn’t perform a task in a way that the user would expect. Using this oracle means that you have some idea of who the user is and some indication of what he or she expects.
  • Inconsistent Within the Product. Something behaves in one way in one part of the product, but in a different way in another part of the product. The change could be related to terminology, look and feel, functionality, or feature set. All you’re doing is pointing out where the product is inconsistent with itself. These are often compelling bugs.
  • Inconsistent with Purpose. In my mind, this is the most compelling of the oracles. It states that the behavior you found is contradictory to what a user would want to do with this software. You might be talking about the purpose of a feature, for example: "Look, I can enter a negative value for headers in this Microsoft Word dialog box." That wouldn’t really be consistent with the purpose of headers and footers, would it? This oracle is often used in conjunction with Inconsistent with Claims or Inconsistent with User Expectations because those oracles also tend to address the purpose of the software.
  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020