C H A P T E R 14 INPUT DESIGN AND PROTOTYPING Chapter Fourteen Prototyping Input Design Define the appropriate format and media for a computer input Explain the difference between data capture data entry and data input Identify and describe several automatic data collection technologies Apply human factors to the design of computer inputs Design internal controls for computer inputs Select proper screen based controls for input attributes that are to appear on a GUI input screen Design a web based input interface Chapter Map Input Design Goal Starts with requirements analysis Capture data Format data in computer form Logical DFD s What Decision Analysis Physical DFD s How How initially captured Methods for transforming to computer form Data Capture Entry and Processing Data capture Data entry the identification and acquisition of new data at its source Source documents are forms used to record business transactions in terms of data that describe those transactions the process of translating the source data or document above into a computer readable format Data processing all processing that occurs on the data after it is input from a machine readable form batch processing the entered data is collected into files called batches and processed as a complete batch on line processing the captured data is processed immediately remote batch processing data is entered and edited on line but collected into batches for subsequent processing Input Implementation Methods Keyboard Mouse Data entered JIT Sound and speech GUI may minimize errors Touch Screen Point of sale terminals Source may be business form Common but error prone Touch Tone Phones Automatic data capture Optical mark recognition OMR Bar codes Optical character recognition OCR Magnetic Ink Input Implementation Methods con t Automatic data capture Electromagnetic transmission Smart cards Biometric Automatic Identification Bar Codes UPC A Bookland Postnet Input Design Guidelines 1 Minimize volume of input Capture only variable data Do not capture data that can calculated or stored in computer programs as constants Stock Number sold Qty are needed Extended Price not need Description not needed Use business codes for appropriate attributes Source Document Form Design Guidelines 2 Source documents should be easy to complete Include instructions for completing the form Minimize the amount of handwriting Data to be entered keyed should be sequenced so that it can be read like a book that is top tobottom and left to right When possible based input design on known metaphors Bad Flow in a Form Good Flow in a Form Metaphoric Screen Design Internal Controls for Inputs Each input and the total number of inputs should be monitored to minimize the risk of lost transactions For batch processing Use batch control slips Use one for one checks against post processing detail reports For on line systems Log each transaction as it occurs Assign each transaction a confirmation number common in webbased systems Validate all data Existence checks Data type checks Domain checks Combination checks Self checking digits Format checks Repository Based Prototyping and Development GUI Components or Controls Common GUI controls for both Windows and Web interfaces Text boxes Radio buttons Check boxes List boxes Drop down lists Combination boxes Spin boxes Buttons Hyperlinks yes also for Windows applications see Quicken 2000 Common GUI Components GUI Components or Controls Advanced controls mostly for Windows interfaces Drop down calendars Slider edit controls Masked edit controls Ellipsis controls Alternate numerical spinners Check list boxes Check tree boxes Advanced GUI Components Advanced GUI Components continued Input Design Process Identify system inputs and review logical requirements Select appropriate input components controls As necessary design any source documents Design validate and test inputs using some combination of Layout tools e g hand sketches spacing charts or CASE tools Prototyping tools e g spreadsheet PC DBMS 4GL A Logical Data Structure for Input Requirements ORDER ORDER NUMBER ORDER DATE CUSTOMER NUMBER CUSTOMER NAME CUSTOMER SHIPPING ADDRESS ADDRESS CUSTOMER BILLING ADDRESS ADDRESS 1 PRODUCT NUMBER QUANTITY ORDERED n DEFAULT CREDIT CARD NUMBER ADDRESS POST OFFICE BOX NUMBER STREET ADDRESS CITY STATE POSTAL ZONE Input Prototype for Data Maintenance Input Prototype for Transaction Input Prototype for Data Maintenance Input Prototype for Web Interface Input Prototype for Web Interface