Information Management

n capturing ( 收集 ) n entering ( 輸入 ) n storing ( 貯存 ) n retrieving ( 檢索 ) n maintaining ( 保存 ) Data Management ( 數據管理 )

Information Management ( 資訊管理 ) n process of managing and processing of data. Data Processing Information

Data Checking n Data Validation ( 數據有效性 ) n Data Verification ( 數據準確性 )

Data Validation ( 數據有效性 ) n check whether the data are reasonable n a set of rules for validating data before the entering of data

Data Validation ( 數據有效性 ) n Example –range check e.g., a month value must be within the range 1 to 12 –limit check e.g., max. working hour per week is <= 80hrs –cross-field check e.g., “sex” field - “M” should correspond “title” field - “Mr”

Data Verification ( 數據準確性 ) n check the correctness of data n data that can pass the verification check are assumed to be correct

Data Verification ( 數據準確性 ) n Example –double keying –check digit like the last number/letter in your ID card –control total

Data Organisation n data are organised as files in the computer system. n Types of data files: Master File ( 主檔案 ) Transaction File ( 處理檔案 ) Backup File ( 後備檔案 ) a file that stores master data that related to particular application, e.g., employee file, customer file a file that contains current transactions which is used to update the information on master file a duplicate ( 複製 ) copy of another file.

Data Maintenance Operations n Add ( 增加 ) –adding new data to files n Delete ( 刪除 ) –deleting of data from files n Edit/Modify ( 編輯 / 修改 ) –changing of data in files

Information Processing n Information processing is the use of transaction files to update the master files. n The two methods are: –batch processing ( 成批處理 ) –real-time processing ( 即時處理 )

Information Processing n Batch processing ( 成批處理 ) n Real-time processing ( 即時處理 ) –update the master file only if the transactions have reached a certain amount/time –e.g., returned books back to shelf in library. –immediate update of the master file after a transaction is made. –e.g., cash withdrawal from an ATM.

Comparison Real-time ProcessingBatch Processing up-to-dateNOT up-to-dateInformation highlow Computer Processing Speed morelessHuman Effort

Information Presentation & Distribution n Typical ways: –softcopy output using monitors –hardcopy output using printers n Normally presented in the following form: –report –document –chart

Information Presentation & Distribution n The most common way to distribute information nowadays is via the network.

Reference n ASL Computer Concepts, Ch. 2 (p.9 - p.17)

Question 2.3 n Why is data control necessary in information processing? What is the difference between “data validation” and “data verification”? Give some examples of data validation methods and data verification methods.

Question 2.6 n Briefly describe what “batch processing” and “real-time processing” are. Give one advantage and one disadvantage of each of the processing method.