Chapter 5 Transactions and Electronic Commerce I. Methods of Data Capture (P.164-P.170) Point of sale (POS) Process control Electronic data interchange (EDI) Web data applications

1. Point of sale (POS) Capture data at the point of sale (the sales register is a computer terminal connected to a central computer). Keyboard (gas station) Bar code scanner (supermarket) Optical character recognition (OCR) reads handwritten zip code Magnetic ink character recognition (MICR) - more accurate than OCR Error detection, computations and immediate update Avoid - rekey data, lost data, duplicate data, inaccuracies, long time, fail to identify error.

2. Process control Manufacturing machines are connected to computers or have built-in computers. Monitor production levels. Monitor quality. Monitor machine uptime or downtime. Problems –standard for various machines –an enormous amount of data: how to use, how to store, how to transmit.

3. Electronic data interchange (EDI) (p.167) The direct computer-to-computer exchange between two firms of standard business transaction documents (invoices, bills, purchase orders, etc.) or send documents through a third- party EDI provider. Cut lead time and improve quality control Lock in customers (easier for customers or distributors to order) Standard and compatibility: software and hardware, data definitions, format of documents, and data conversion.

4. Web Database Applications Why do business on the Web? –Expanded reach –Corporate image enhancement –Improved customer service –Follow-up sales/marketing material –New product/service delivery channel –Reduced operating expenses –Test marketing (new products, new services, new market campaigns)

Web database applications –Advertising –Customer services –Financial servicesFinancial services –Information collection and search enginesearch engine –Job recruitmentJob recruitment –Luxury productsLuxury products –Real estateReal estate –Virtual shopping mallsVirtual shopping malls

1. B2C Prepurchase Information Purchase Postpurchase support 2. B2B Buyers know what products they want Buy in bulk Make repeat purchase II. E-Commerce (P.170)

1. Primary measures of data quality Data integrity Multitasking and concurrency problems Data volume & Performance Summary measures and details Time Example of problems: P.180 Figure 5.15 III. Data Quality (P P.183)

Data integrity It means keeping data accurate and correct. –Reduce error: avoid reentry and build in error detection –Validation: avoid missing data, and eliminate inconsistency –Immediate update

Multitasking and concurrency problems –Multitasking OS: run more than one jobs at the same time –Concurrency problems in multiuser environment: different applications modify the same piece of data at the same time –Example. P.182 Figure 5.16: 200? 850? or 550? Need software to lock out all users except one.

Data volume –Systems slow down –Difficulty for data integrity –Storage –Obsolete data Time (deadline, timing)