Interface Design ITD34003 Lecture Notes PDF

INTERFACE DESIGN ITD34003 CHAPTER 5 : INPUT AND OUTPUT DESIGN  Input Design Basic Principle of Input Design 2 Objectives 1. The goal is to simply and easily capture accurate information for the system 2. Reflect the nature of...

INTERFACE DESIGN ITD34003 CHAPTER 5 : INPUT AND OUTPUT DESIGN  Input Design Basic Principle of Input Design 2 Objectives 1. The goal is to simply and easily capture accurate information for the system 2. Reflect the nature of the inputs 3. Find ways to simplify their collection 3 Online VS Batch Processing Online processing immediately records the transaction in the appropriate database Batch processing collects inputs over time and enters them into the system at one time in a batch Batch processing simplifies data communications and other processes; master files are not updated real-time 4 Capture Data at the source Reduces duplicate work Reduces processing time Decreases cost Decreases probability of error 5 Source Data Automation Can be obtained by using the following technologies: – bar code readers – optical character recognition – magnetic stripe readers – smart cards – RFID (radio frequency identification tags) How can the internet be used for source data automation? 6 Bar Code Readers 7 Optical Character Recognition 8 Magnetic Stripe Readers 9 Smart Card Readers 10 RFID 11 Minimize Keystrokes Never ask for information that can be obtained in other ways – Lookups – Dropdown lists – Default values 12 Lookups 13 Dropdown lists 14 Default values 15 Types of Inputs 1. Data items linked to fields 2. Text 3. Numbers 4. Selection boxes Check boxes Radio buttons On-screen list boxes Drop-down list boxes Combo boxes Sliders 16 Example 17 Types of selection box (1) Check Box – Lists all alternatives with box to select – Enables multiple alternatives from list – Alternatives may not be mutually exclusive – No negatives alternatives – Box labels should be ordered – Max. 10 alternatives (if >10 use subcategories) 18 Types of selection box (2) Radio Buttons – Lists all mutually exclusive alternatives, each with circle to select – Enables single unique alternative from list – Max. 6 alternatives (if >6 use drop-down list box) – If 2 alternatives, use one check box instead – Avoid radio buttons & check boxes 19 Types of selection box (3) On-screen list box – List of alternatives in a box – Only use if no room for check boxes or radio buttons – Enables single unique alternative c.f. radio button or multiple alternatives (c.f. check boxes) – Alternatives in list can be scrolled Drop-down list box – Selected item in one-line box, box opens to reveal alternatives – Use when no room to display all alternatives – Similar to radio buttons but more compact – Hides alternatives until opened – Simplifies design if no. of alternatives is unclear 20 Types of selection box (3) Combo box – Drop-down list box for keyboard entry with scrolling – Use as a shortcut for experienced users Slider – Graphic scale with a sliding pointer to select a number – Used when entering an approximate value from large continuous scale – Slider selection of value is inexact – Can include updating number box to indicate the current exact value on scale 21 Types of Input Validation (1) All data must be validated to ensure accuracy = at least one check, ideally ALL appropriate checks (URR = “think” Units, Range, Resolution) Data failing any check should be rejected until valid 22 Six different kinds of check Completeness check Ensures all required data has been entered Used when several fields must be completed before the form can be processed If any of the required data is missing, incomplete for re- presented to the user, e.g. with required fields highlighted 23 Six different kinds of check Format check - Ensures data values are the correct type and in the correct format - Used when fields contain numeric values or values are codes - Ideally, values are not entered as text, if the string is entered it must be convertible to a numeric value - If coded values have a format, values must be checked against the format 24 Six different kinds of check Range check Ensures data values are within the specified range Used with ALL numeric data Can include logical checks e.g. implied age >110 years Check digit check Check digits added to numeric codes Used for all numeric codes 25 Six different kinds of check Consistency checks – Ensures data combinations are valid – Used when data values are related – Related data common, e.g. date of birth precedes date of driving license issue – System prompts for invalid related values to be consistent 26 Six different kinds of check Database Checks Data values compared with stored (correct) values Used when critical values are already stored (elsewhere) e.g. National Insurance number Usually performed after all other kinds of check Possibly opening database (or file) and always reading requires extra processing so only validated valued are queried and compared for correctness 27  Output Design Basic Principle of Output Design 28 Objectives The outputs are what the system produces : on the screen on paper or in other media (Web or Mobile) Serve the intended purpose Deliver the right quantity of output Deliver it to the right place Provide output on time Choose the right method 29 Basic Principles Understand Report Usage Manage Information Load Minimize Bias 30 #1 Understand Report Usage Reports are used to identify specific items or used as references to find information, so the order in which items are sorted on the report or grouped within categories is critical. Web reports that are intended to be read from start to finish should be presented in one long scrollable page, whereas reports that are used primarily to find specific information should be broken into multiple pages, each with a separate link. Page numbers and the date on which the report was prepared are also important for reference reports. 31 #1 Understand Report Usage Real-time reports provide data that are accurate to the second or minute at which they were produced (e.g., stock market quotes). Batch reports are those that report historical information that may be months, days, or hours old, and they often provide additional information beyond the reported information (e.g., totals, summaries, and historical averages). 32 #1 Understand Report Usage There are no inherent advantages to real- time reports over batch reports. The only advantages lie in the time value of the information. If the information in a report is time critical (e.g., stock prices, air- traffic control information), then real-time reports have value. 33 #2 Manage Information Load Most managers get too much information, not too little (i.e., the information load that the manager must deal with is too great). The goal of a well-designed report is to provide all the information needed to support the task for which it was designed. 34 #2 Manage Information Load This does not mean that the report needs to provide all the the information available on the subject—just what the users decide they need in order to perform their jobs. In some cases, this can result in the production of several different reports on the same topics for the same users because they are used in different ways. 35 #3 Minimize Bias No analyst sets out to design a biased report. The problem with bias is that it can be very subtle; analysts can introduce it unintentionally. 36 #3 Minimize Bias Bias can be introduced by the way lists of data are sorted because entries that appear first in a list can receive more attention than those later in the list. Data are often sorted in alphabetical order, making those entries starting with the letter A more prominent. Data can be sorted in chronological order (or reverse chronological order), placing more emphasis on older (or most recent) entries. Data may be sorted by numeric value, placing more emphasis on higher or lower values. 37  #3 Minimize Bias For example, consider a monthly sales report by state. Should the report be listed in alphabetical order by state name, in descending order by the amount sold, or in some other order (e.g., geographic region)? There are no easy answers to this, except to say that the order of the presentation should match the way the information is used. 38 Bias in Graphs 39 Bias in Graphs youtube 40 Types of Output 41 Detail Report 42 Summary Report 43 Turnaround document 44 Graphs 45  Summary The fundamental goal of navigation design is to make the system as simple to use as possible The goal of the input mechanism is to simply and easily capture accurate information The goal of the output mechanism is to provide accurate information to users that minimize information overload and bias