What are the cons of prototyping

In today's increasingly global world of the Internet, hardware and software are also becoming more and more complex. With this development, the demands on usability are getting higher and higher, since the product has to meet an increasing mass of users with different demands and skills. To increase this usability, many techniques have been developed in recent years. One of them is called paper prototyping. Since this technology is often only used in large companies, the following question arises for most private individuals: "What is paper prototyping, how does it work and why does it make sense to use it?"

1. Definition of paper prototyping

Paper prototyping is a variation of the usability test in which representative users perform realistic tasks by interacting with an interface created on paper that is manipulated by another person ("playing the computer"), but who does not explain how the interface is intended is to work. [1]

1.1 history

Paper prototyping began around the early 1990s. Authors such as Bob Virziu, Jakob Nielsen and Tom Tullis, who are by no means the only ones, are using the concept of "low-fidelity" prototyping for the first time. Although similar techniques were used by large companies in the 1980s, paper prototyping, as it is used by the general public today, has only existed for about 10-15 years.

1.2 Brief description of the functionality

First of all, a team of knowledgeable people must be put together to carry out the test. Then a representative group of test persons has to be selected that represents the central target group of the interface to be tested. In the following, the team has to put together special tasks that cover the functionality of the interface as completely as possible.

The team then begins to sketch all the menus, displays and data on paper that are necessary to represent and carry out the selected tasks.

After the prototype has been created, the actual test is carried out. The users are asked to carry out the tasks set by interacting directly and only with the existing interface. One member of the team has to make sure that the user can do this by playing the computer and manipulating the sketches so that it appears to the user as if they are working on the computer. This is also called the “Wizard of Oz '” because the interface works miraculously even without implementation. Another team member is in the test the so-called facilitator, who leads the test run and explains to the user what to do and also ensures that the user always explains why he is performing his actions while silent Observers follow the experiment and note down all relevant information. From this information it can be seen with little effort which parts of the interface work well and which need rework or redesign. This also has the advantage that the prototype is in paper form: Changes can be made very quickly on paper (even during the test) and the grossest errors can be eliminated very quickly.

1.3 Low and high fidelity prototyping

This concept is one way of classifying prototypes. While low-fidelity prototyping (low-fi) seems clearly fake to the user, hi-fidelity prototyping (hi-fi) is created in such a way that it almost looks like the end product and is often confused with it by the users. In addition, hi-fi is mostly programmed or created with appropriate software. The goal of both classes is the same, however, and while it is a seemingly useful concept, it would sometimes be misleading to apply this concept to an entire prototype, as no clear line can be drawn between the two classes. Therefore it is better to speak of Fidelity only for certain parts of the prototype.

1.4 Horizontal and vertical prototyping

Another concept for classifying prototypes is to divide them into horizontal and vertical prototyping. Horizontal prototyping means that the aim of the prototype is to cover the product as completely as possible and to test all features. The breadth of the test comes at the expense of accuracy, of course. In contrast, there is vertical prototyping, which is limited to a certain feature of the product, but tests it with the greatest possible accuracy. The goals of both classes differ, of course: While horizontal prototyping helps to evaluate and test general usability areas such as navigation, feature placement or general design, the goal of vertical prototyping is to improve the usability of a certain feature and to improve it towards the user cut to size.

2. Advantages and disadvantages of paper prototyping


  • No technical knowledge is required to produce paper prototypes.
  • It is a direct kind of communication between the developers and the customers, as no technical aspects have to be taken into account.
  • The effort (time, costs) is very low, so that a large number of tests can be carried out in the individual development stages of the interface.
  • A usability assessment of the user can be given via the interface before the implementation has even started.


  • Certain problems cannot be identified because they only occur with the implementation
  • The flood of information can become very confusing if not optimally planned.
  • If the users are chosen incorrectly, the design may develop in the wrong direction.

3. Use of paper prototyping

The following is an overview of how to create paper prototypes.

Just as in a successful software project you do not start programming blindly in the first class that occurs to you, it is also best when creating a paper prototype to make some preparations before sketching the interface. "[4 ]

3.1 Materials

The most important material a paper prototype uses is of course paper and pen. Although entire prototypes can only be produced with this material, it is helpful to use other materials as well to simulate certain functionalities of the interface. There are no limits to the creativity of the team. For example, small self-adhesive notes can be used to simulate check boxes, which the user can tick by “clicking” on them, while the team member playing the computer simply sticks the note with a painted X on the box. Right-click menus can also be efficiently simulated using these notes. Furthermore, it is advisable to use soluble, transparent adhesive tape again for text boxes in which the user is supposed to write, in order not to have to make a new prototype for each test run.

3.2 Background

A background is a scheme that does not change throughout the test. This can either be a framing interface that the user should always see, for example the back and forth buttons in a browser, as well as the display of a hardware cover, such as a picture of a cell phone, in order to test its software. A background helps the user focus on the prototype and can create a certain consistency. This can be achieved, for example, by repeatedly recurring schemes, such as the same control elements on cell phones, etc. Furthermore, a background creates a certain clarity for the intermediary, since with many papers on the table it can always be seen which parts of the prototype the user can interact with at the moment.

3.3 simulation

Most of the techniques used in reality can be simulated with a few tricks:

  • Tooltips / mouseover

    It must be explained to the users beforehand that there are tooltips in this test. To use this, the user has to point to an element and ask the intermediary "What is this?"

  • Rollover / pop-up menus

    Can be simulated using self-adhesive notes

  • Single notes

    The mediator simply has to say “beep” at this point.

  • Drag and drop

    Since it is very difficult to implement, the user has to tell the intermediary what to move where.

  • Right click

    Works like normal pop-up menus

  • Slider, progress bar

    In the case of sliders, the user must indicate which value he would like to set the slider to. With progress bars, the intermediary has to tell the user what it is about.

  • Website links

    It must be explained to the user beforehand that he can ask for each picture or piece of text whether it is a link. This makes it possible to quickly find out where users would intuitively suspect a link and where they would like to have them.

  • Scrolling

    Scrolling can be simulated using a rectangular cut-out template, which contains a scroll bar on the right-hand side. Scrolling can be simulated by moving the content up and down.

4. Task design

In order to conduct an informative test, the tasks that users complete must be well chosen. Good assignments are made up of two different areas: one includes the questions the developers have about the design, the other, the goals of the users.

A good task design usually involves the following steps:

  • Define the user goal and use of the interface
  • Developer questions, such as listing potential issues, risks, and other concerns
  • Assign different priorities to the questions
  • Select the task in such a way that as many important questions and goals as possible are covered.
  • Repeat the fourth step until you have put together a set of tasks that cover as many questions as possible.
  • Determine the order of the tasks and create a schedule. Care must be taken that the test does not take up too much time.
  • Formulate the instructions that will be given to users in the test.
  • Test the tasks in practice.

The people who work out the tasks should be made up of people from the team as well as others who have specific questions or want to test a specific feature.

5. Usability test with paper prototyping

Before the actual test, a few points must be observed in order not to throw the user into the deep end. In addition to introducing everyone involved, it should be made clear to the user what will happen here. In addition to general processes, such as filling out general test forms, the main focus is on explaining to them that the interface is being tested and not the user. If the test is recorded by camera or other media, this must also be indicated to the user.

This must be given a brief introduction to how the test works, taking care not to tell the user too much about its objectives and functions.

It starts by explaining to the user what he has in front of him, how to interact with it, and what the task is to be performed. As little as possible should be spoken to the user on questions within the test, as this could influence the result.

During the test, the facilitator must also consider the following important points:

  • Users should point, not speak. Although users should think out loud to understand what they are doing, care should be taken not to use verbal explanations such as "now I would like to start over". Such things are more likely to show users how to do it and explain why.
  • It is important for users to understand that it is okay to write on the prototype; often, users are inhibited from writing on the prototypes.
  • Be careful about computer errors. Sometimes computers (in this case, people simulating the computer) make mistakes. Should this happen, the computer must be made aware of this by means of subtle notices.
  • You have to be prepared for unpredictable actions by the user. Also, it often happens that the users do things that are theoretically allowed but were not intended and that there is no longer any follow-up action. In this case, the test can either be restarted or intercepted by a "back" function and a corresponding message that it cannot go any further here.
  • If the test is stuck in a dead end, pause before repeating the test In such cases, it is important to make it clear to the user that what happened is very good because they uncovered a major design flaw. Then, before the test can be restarted, it must be clarified exactly how the error came about.

The observers, however, should limit themselves to the following

  • Presence for the entire duration of the test
  • Keep calm while the user is working
  • Pay attention to your own body language
  • Don't give any help
  • Don't ask design questions (users aren't designers!)
  • Pay attention to data protection

6. Final remark

Paper prototyping is a very useful technique that can simplify design work many times over. However, it is only one technique among many others that is used in user-oriented design today.

The decision to use paper prototyping is different for each product.

There are also many other ways to keep usability high without extensive testing. But above a certain complexity, paper prototyping is used again and again because it currently offers the best “price-performance ratio”.

“Paper prototyping can help you avoid great frustration by improving applications that you design before you even start implementing. Previously misunderstood, paper prototyping gained wide acceptance during the 1990s and is now used in most well-known companies. ”[4]


[1] Snyder Carolyn. 2003. Paper Prototyping: The Fast and Easy Way to Design and Refine User Interfaces

[2] Rudd, J., K. Stern, and S. Riihiaho. 1996. Low vs. Hight Fidelity Prototyping debate. Interactions January: 75-85

[3] http://www.medien.ifi.lmu.de/lehre/ws0607/mmi1/mmi-uebung4.pdf

[4] http://today.java.net/pub/a/today/2003/12/23/sixSigns.html

[5] http://guir.berkeley.edu/courses/SummerHCI04/readings/Paper%20Prototyping.htm

[6] http://www.infodesign.com.au/usabilityresources/design/paperprototypinggraphics.asp

Status of the website: January 2007