LIM, MARYLYN GRACE C.

OOA

            Book: Systems Analysis and Design: an Active Approach

            Author: George M. Marakas

            Reference No.: QA

                                    76.9

                                    S88

                                    M37

                                    2001

Chapter 11: Designing the Inputs and User Interface

Quote: “We’ve all heard that a million monkeys banging on a million typewriters will eventually reproduce the entire works of Shakespeare. Now, thanks to the Internet, we know this is not true.”

Review:

            After designing the system output, it’s now time to design the inputs and user interface. This chapter discusses things related to the capture and input of the data needed to create the required system outputs. Also, this chapter focuses on the design characteristics of well-designed user interfaces. This chapter also has topics of different controls available for the analyst to insure high integrity and accurate input data.

            There are 5 basic categories of human-computer interaction. 1.) Command dialogue. This approach lets the user to initiate all dialogue by issuing instruction to the computer via a structured syntax of commands. 2.) Menus. This shows a list of available alteration for the users that are relevant to the task being performed. 3.) Icons and buttons. This shows an iconic menu that helps the user to select and execute commands by pointing and clicking at graphical buttons/icons located on the menu bar. 4.) Input screens and forms. This uses a screen-based form that helps the user to fill in the needed information in the space provided in such a way that all data are retrieved in a logical and easy-to-read manner. 5.) Natural language recognition. This approach uses a voice synthesis technology to help the user to interface with the computing device by using natural language and voice commands.

            There are 3 common input devices used. 1.) Biometric input devices. Thru this device, unauthorized access to the system can be prevented. This refers to an automatic identification of a person based on his/her behavioral characteristics. 2.) Optical input devices. This includes devices like barcodes, optical mark reading and optical character recognition. Barcodes are used so that it will allow data to be collected faster and accurately. Optical mark reading senses marks in predefined areas of a special form. Optical character recognition scans any form of document as long as it contains numbers, letters or marks. 3.) Smart cards. This allows a huge amount of information to be stored, accessed and processed whether it is online or offline.

            There are 4 guidelines to be remembering in input and interface design. 1.) human-computer interaction. This includes desktop metaphor which creates an electronic environment that allows direct manipulation of the multiple items on the desktop. This also includes document metaphor which helps the user to easily navigate between documents. Lastly, this includes dialogue metaphor which creates an electronic version of a conversation using natural language. 2.) Data entry issues. This includes consistency that is the most important characteristics of a good data entry. 3.) Providing user feedback. This includes a feedback loop which is a closed path that maintains a prescribed relationship between output signals and input signals. 4.) Dialogue design. This defines the conditions under which input is captured and conveyed.

            Lastly, this chapter talks about designing the input controls. There are 2 basic categories in designing input controls. 1.) Data controls. This helps prevent errors in the system. 2.) Access controls. This prevents unauthorized person from accessing the system.