Chapter 9 Review Questions

Why is capturing data at the source important?

Capturing data at the source has three advantages. First, it can reduce costs because work does not have to be duplicated. Second, it reduces delays in processing. Third, it reduces the likelihood of error.

Explain the differences between object-action order and action-object order.

Commands given to the system usually follow a sequence of 'specify the object, then specify the action' or 'specify the action, then specify the object.' This is referred to as the grammar order of the commands. The designers should select the grammar order desired for the system and use it consistently.

Why is consistency in design important? Why can too much consistency cause problems?

Consistency means that all parts of the same system work in the same way. This enables the users to predict what will happen because a function in one part of the system works the same way in other parts of the system. Users will be confident as they work with different parts of the system if they can predict the behavior of functions throughout the system. The problem with too much consistency is that sometimes the users don't differentiate forms or reports that look very similar to each other, and inadvertently use the wrong one. So, in these cases, there should be enough unique characteristics to distinguish each form and report from the others.

Why is content awareness important?

Content awareness means that the interface makes the user aware of the information delivered through the interface with the least amount of user effort. This is important because if the user is constantly aware of where he is and what he is seeing, he will find the system much easier to use and his satisfaction will be high.

What is context-sensitive help? Does your word processor have context-sensitive help?

Context-sensitive help means that the help system recognizes what the user was doing when the help was requested, and help specific for that task is displayed. MS Word does have context-sensitive help.

Describe five types of inputs.

1- Text boxes are areas defined on the screen where the user enters text. The text can be a single line or a scrollable region. Text boxes are used whenever the user needs to enter free-form data. 2- Number boxes are used when the user must enter numeric data. 3- Check boxes are used whenever the user can choose one or more items from a known list. 4- Radio buttons are used when the user needs to select one choice from a known set of options. 5- List boxes present the user with a list of items from which one is selected.

How would you improve the form in Figure 9-4?

A user who has not seen this form before and does not know how it is used will find it difficult to make suggestions for improvement. The form is very dense, however, and so it might be useful to segment it into two pages that are logical subsets of the form content. Each page could be much less dense and therefore easier to use.

What are the key factors in designing an error message?

An error message should first identify the error. Some additional explanation of the problem is also usually provided. Then, the message should inform the user how to correct the problem. Finally, a button for user response is usually included that clears the message off the screen and enables the user to take the corrective action.

Why is it important to perform an interface evaluation before the system is built?

An interface assessment is important before the system is built because we need to do as much as we can to improve the interface design prior to implementation. It is wasteful to wait until after implementation to evaluate the interface because it will be expensive to go back and modify the interface at that point.

What is an interface structure diagram (ISD) and why is it used?

An interface structure diagram shows all the screens, forms, and reports in the system, how they are related, and how the user moves from one to another. The diagram helps depict the basic components of the interface and how they work together to provide users the needed functionality. The structure of the interface depicted in the ISD can be examined using the use cases to see how well the use cases can be performed. This is an important early step in developing simple paths through the most common activities performed in the system.

Describe five types of input validation methods.

Completeness checks are performed to verify that all required data items have been entered. In some cases, data is optional in a transaction. However, when specific data is required, a completeness check will ensure that something is entered in every required field. Format checks are used when a particular data format is expected in the field and can be verified.. Range checks are commonly used when a numeric item falls within some expected range of values. A check digit check is used to validate numeric code fields. In these situations, an algorithm establishes a check digit for each occurrence of the numeric code. Whenever a numeric code is re-entered into the system its check digit is recalculated. If the calculated check digit does not match the expected check digit, there has probably been a data entry error in the code, and it needs to be re-entered. Consistency checks are performed when there is a relationship between field values that is known and can be checked. Database checks are used to compare an entry against a value stored in a file or database to ensure it is a valid value.

Describe five types of outputs.

Detail reports are reports that only list detailed information about a few items. Detail reports are designed for situations where complete information is sought. Summary reports list summarized information about a large number of items. Exception reports list information only about items that meet some predefined criterion (e.g., accounts over 30 days past due). Turnaround documents provide information about some system output (e.g., a bill), but also include a section that will re-enter the system as an input (e.g., a payment coupon). A graph is a depiction of numerical relationships using a two or three dimensional chart.

Describe five types of messages.

Error messages are displayed when the user has done something that is not permitted or cannot be carried out. An error message should inform the user why the attempted action is illegal or incorrect. Confirmation messages are displayed whenever the user has entered a command that has major significance and may be destructive (such as shutting down the system or deleting a record.). The confirmation message is used to force the user to verify that the action is the correct one. Acknowledgment messages signify that an action or task is complete. These messages can be used to ensure that the user knows what the system is doing, but they can become very annoying if encountered frequently. Delay messages indicate that the system is performing a task and that the user should wait until the task is completed. These messages keep the user informed about the system status, and can be very helpful, especially to novice users who may not appreciate the time certain tasks require. Help messages provide the user with additional information, and are an important means of giving users instructions and guidance when needed. Even experienced users will need access to help for rarely used system functions.

How can a system be designed to be used by both experienced and first time users?

Experienced users prefer systems that focus on ease of use, while novice users prefer systems that are easy to learn. These two goals are not necessarily mutually exclusive. Generally, systems should be set up so that the commonly used functions can be accessed quickly, pleasing the experienced users. To assist the novice users, guidance should be readily available, perhaps through the "show me" functions that demonstrate menus and buttons.

Describe the basic process of user interface design.

First, identify 'use cases' that describe commonly used patterns of actions that users will perform. These use cases will be valuable in ensuring that the interface permits the users to enact these use cases quickly and smoothly. Next, develop the interface structure diagram, defining the basic structure of the interface (screens, forms, and reports) and how the interface components connect. Third, develop interface standards, the basic design elements that will be used throughout the interface. Fourth, create prototypes of the various interface components (navigation controls, input screens, output screens, forms, and reports). Finally, evaluate the prototypes and make changes as needed.

Under what conditions is heuristic evaluation justified?

Heuristic evaluation is probably justified in situations where the interface is well understood. When there is little uncertainly about how the interface should function, then it is probably sufficient to just assess it internally by comparison to a checklist of design principles. It would be dangerous to use this technique (which does not involve users) if there was uncertainty about what should appear in the interface or how it should function.

Why is input validation important?

Input is validated in order to try and reduce the amount of erroneous data that is entered into the system. Clearly, the quality of the information that comes out of a system is dependent on the quality of the input data. Therefore, we must do as much as is reasonable to assure high quality data is input in the system. The various techniques of data validation help us do that.

Why are interface standards important?

Interface standards help define the basic, common design elements in the system. These standards help ensure consistency throughout the system.

Compare and contrast check boxes and radio buttons. When would you use one versus the other?

Physically, check boxes are usually represented as small squares, and radio buttons are small circles. Operationally, they are used very differently. Check boxes are used when the user can select one or more choices from a list of options. Radio buttons are mutually exclusive. Only one button can be chosen at a time. Selecting one radio button removes the selection from any button previously selected. Use radio buttons when you want to force the user to make one choice. Use check boxes when the user can select multiple items from the list.

Why do we prototype the user interface design?

Prototyping helps the users and programmers understand how the system will perform. Prototypes can be very useful in helping the users conceptualize how they will actually work with the system, and prototypes can help identify problems or misconceptions in the interface before it is actually implemented.

Compare and contrast the three types of interface design prototypes.

Storyboards are really just pictures or drawings of the interface and how the system flows from one interface to another. HTML prototypes are web pages that show the fundamental parts of the system. Users can interact with the system by clicking buttons and entering data, moving from page to page to simulate navigating through the system. Language prototypes create models of the interface in the actual language that will be used to implement the system. These will show the user exactly what the interface will look like, which is not possible with the other two methods.

Explain three important user interface design principles.

The authors list six principles of user interface design: • Layout - the interface should be a series of areas on the screen that are used consistently for different purposes. • Content Awareness - the user is always aware of where they are in the system and what information is being displayed. • Aesthetics - interfaces should look inviting and should be easy to use. • User Experience - experiences users prefer ease of use, while inexperienced users prefer ease of learning. • Consistency - users can predict what will happen before a function is performed. • Minimize Effort - interface should be simple to use.

How can different parts of the interface be consistent?

The navigation controls can be consistent, using the same icon or command to trigger an action throughout the system. Terminology can be consistent throughout the interface. The content portion of the screen that contains forms and reports should also present consistently designed reports and forms. Messages and information in the status area should be specified consistently throughout the system.

Compare and contrast the four types of interface evaluation.

These techniques vary in terms of the degree of formality and the amount of user involvement. Heuristic evaluation involves assessing the interface based on a checklist of design principles. This assessment is usually performed by team members, who independently assess the interface and then compare their assessments. Weaknesses that are common in all the evaluations then point to areas that need modification. Users are not involved in this process. In a walkthrough evaluation, the users see the interface at a meeting presentation, and they are "walked-through" the parts of the interface. The interactive evaluation can be used when the prototype as been created as an HTML or language prototype. The users can actually interact with the interface as if they were using the system, and can give direct comments and feedback based on their experience. Problems or areas of confusion can be noted and corrected by the team. Formal usability testing has the users interacting with the interface without guidance from the project team. Every move made by the user is recorded and then analyzed later in order to improve the interface.

How can you prevent mistakes?

While it is impossible to completely prevent mistakes, there are some things that will help the user avoid mistakes. First, make sure all commands and actions are clearly labeled. Limit the number of choices that are presented to the user at one time to help reduce confusion. Never display a command or action that is inappropriate for the situation. Also, give users a chance to confirm potentially destructive actions (such as deleting a record).

What is white space and why is it important?

White space refers to areas on an interface that are intentionally left blank. The more white space on an interface, the less dense the information content. Designers need to try and strike a balance between information content and white space. Some white space is necessary to help the users find things on the interface. Generally, more experienced users need less white space than novice users.

What do you think are three common mistakes that novice analysts make in interface design?

• Failing to focus on the most common paths through the interface • Making the interface too crowded • Failing to think about whether the primary users of the system are casual, occasional users or frequent, experienced users • Being inconsistent from one place in the interface to another in terms of standard design features and terminology

What are three fundamental parts of most user interfaces?

• Navigation mechanism - the way the user gives instructions to the system and tells it what to do. • Input mechanism - the way in which the system captures information • Output mechanism - the way the system provides information to the user or to other systems.

Under what circumstances would you use a drop-down menu versus a tab menu?

A drop-down menu is commonly used as the second-level menu, triggered when one of the main menu options is selected. The drop-down menu lists another set of more specific commands that will either lead directly to an action or to another, more detailed menu. The tab menu is chosen whenever the user needs to make multiple choices (such as specifying several settings) or perform several related commands. The tab menu stays open until the user has completed making the choices and closes the menu. Use a tab menu whenever the user needs to do several related tasks at one time.

Describe four devices that can be used for source data automation.

Bar code readers scan bar codes found on products to enter data directly into the system. Optical character readers can read and enter printed numbers and text.Magnetic stripe readers enter information from a stripe of magnetic material. Smart cards contain microprocessors, memory chips, and batteries to maintain information which then can be read by smart card readers.

Why are menus the most commonly used navigation control?

Menus are the most commonly used navigation control because they are much easier to learn than a language, and they are very simple to work with, enhancing the ease of use of the system.

What type of interface evaluation did you perform in the Your Turn Box 9.1?

This is an example of heuristic evaluation, since the interface is being compared to a set of design principles.

Describe three basic principles of navigation design.

• Prevent Mistakes - this principle is directed toward developing the navigation controls to help the user avoid making mistakes. • Simplify Recovery from Mistakes - this principle recognizes that mistakes will happen, and so is directed toward making it as easy as possible to recover from those mistakes. • Use Consistent Grammar Order - This principle states that the order of commands should be consistent throughout the system.

Explain three principles in the design of outputs.

First, it is important to understand how the report will be used. It is not enough just to know what data should appear on the report. The report designer needs to know how the user will utilize the report; what sequence or sorting arrangement is needed, what subtotals are needed, when the information is needed, etc. Second, the report design needs to manage the information load presented in the report. A report that dumps in 'everything but the kitchen sink' will probably not be useful to the recipient. Have the user specify the question(s) he wants to answer by using the report, and then provide just the information needed to answer those questions. Third, avoid presenting the information in a biased way. Bias can be unintentional, so carefully assess choices made on information sorting or structuring graphical outputs.

Under what circumstances should densities be low? High?

Low densities are preferred by infrequent or novice users of an interface. These users will be unfamiliar with the interface and will be helped by having a balance of information and white space on the interface. High densities can be acceptable to experienced users of the interface, because they are highly familiar with the information on the interface and do not need as much white space to help them find what they are looking for.

Compare and contrast on-screen list boxes and drop-down list boxes. When would you use one versus the other?

On-screen list boxes present the user with a list of choices that are always displayed. A drop-down list box displays the list of choices as needed. Generally, there is not enough screen space to use on-screen list boxes unless the list is quite short. Therefore, the drop-down list box is used to display longer lists temporarily and then disappear from the screen after the choice is made. The amount of available screen space dictates which type of list box will be used.

Compare and contrast batch processing and on-line processing. Describe one application that would use batch processing and one that would use on-line processing.

Online applications process the entire transaction, including updates to the files or databases, immediately when the transaction occurs. Batch applications, on the other hand, accumulate transactions over some time period, then process all transactions from the batch completely and post them to the files and databases at one time. An airline reservation system is a classic example of an online system, since the flight reservation is immediately reflected in the system database. Payroll systems are commonly batch applications, with payroll transactions accumulated over the pay period and processed as a batch at one time.

When would you use electronic reports rather than paper reports, and vice versa?

Paper reports have the advantage of being permanent, easy to use, and portable (if they are small). Paper reports do not require the presence of a computer in order to be used. A report should be printed on paper if its content is fairly static and if it needs to be taken from place to place to be used, and computers are not readily available. Electronic reports store the reports on servers so that they can be readily viewed from any computer. Electronic reports are so inexpensive that often many variations of the reports are created. Users can refer to the reports online or print them locally as needed. It is generally advantageous and less costly for users to print reports locally as needed rather than printing all reports centrally.

Compare and contrast four types of menus.

The menu bar is usually the main menu of the system. It consists of a list of commands across the top of the screen that is always displayed. The commands on the menu bar represent the main objects and/or actions of the system, and lead to other menus. Drop-down menus appear immediately below another menu. A series of commands are listed, and these lead to direct actions or other menus. The drop- down menu disappears after one use. Pop-up menus appear to 'float' on the screen, usually triggered by a right-click on the mouse. A series of commands that pertain to the work the users was doing are listed. Pop-up menus are often used to present an experienced user with shortcuts to common commands. Pop-up menus disappear after one use. A tab menu is a multi-page menu, each page represented by a tab on the menu. Each tab represents a set of related actions or settings. The tab menu will remain on the screen until the user closes it.

Explain three principles in the design of inputs.

The most significant input design principle is to capture data as close to its point of origin as possible. By electronically collecting the data at its point of origin, time delays are minimized and errors can be reduced. A second important input design principle is to minimize user keystrokes. Use source data automation techniques whenever possible. Only ask the user to enter new data into the system; use reference tables and lookups whenever possible. When the inputs have known values, use default values check boxes, radio buttons, or drop-down lists. Finally, use the appropriate mode of processing (online versus batch) for the application. Batch applications are generally simpler than online applications, but have the disadvantage of not updating the databases or files immediately. Online applications are more complex than batch, but are used when it is necessary to have immediate update of the databases or files.

What are use case scenarios and why are they important?

Use cases describe commonly used patterns of actions that users will perform. Use cases describe how users will interact with the system. Use cases are developed for the most common ways of working through the system. These use cases will be valuable in ensuring that the interface permits the users to enact these use cases quickly and smoothly.

Describe four types of navigation controls.

• Languages - most often this navigation control refers to a command language, or a set of specials instructions that are used to instruct the system. In order to perform a task the user must know the correct command to give the system. Natural language interfaces free the user to give instructions in everyday terminology, but these types of systems are not common. • Menus - this navigation control presents the user with a list of options that can be performed as needed. Menu structures present the user with an organized set of commands to apply • Direct manipulation - this type of navigation control involves working directly with interface objects, such as dragging a file from one location to another. • Voice recognition - this navigation control involves giving instructions to the computer verbally. Some of the systems only recognize certain commands, while others recognize more natural speech. Progress is being made in this technology, but it is not yet common in systems.

Explain the purpose and contents of interface metaphors, interface objects, and interface actions, interface icons, and interface templates.

• The interface metaphor provides a concept from the real world that helps the user understand the system and how it works. If the user understands the metaphor being used, he will probably be able to predict where to find things and how things will work even without actually using the system. • Interface objects are the fundamental building blocks of the system. Object names should be based on the most understandable terms. • Interface actions specify the navigation and command language style and the grammar of the system. Action terminology is also defined. • Interface icons are pictures that are used to represent objects and actions in the system, often shortcuts, that are available throughout the system. • The interface template defines the general appearance of all screens in the information system and all forms and reports that are used. The template consolidates all the other major interface design elements - metaphors, objects, actions, and icons.