Using Databases to Facilitate Learning

and Develop Inquiry Skills

Definitions, Planning and Design Issues, Higher-Order Thinking Skills,

Advantages and Disadvantages

What Can You Do with a Database ?

Databases can be used to: 4  Analyze, collect, and manipulate data. 4  Foster problem-solving activities

(planning, organizing, categorization, dissemination, and logical thinking).

4  Create an environment for inquiry. 4  Classify and group data.

Definitions

4  A database is a collection of related fields grouped into records.

4  Fields are the smallest unit of data and are useless by themselves. All fields related to a particular subject form records.

4  Records are used to represent all the information pertaining to one person, place, topic, or thing.

4  The conglomeration of records forms the database.

Thoroughly understand: 4  The data to store and manipulate. 4  The interdependencies among data. 4  The reason why the data exists. 4  The types of problems that can be solved

using the data. 4  The ways data can be managed and

manipulated to produce a useable product.

Steps to Complete Before Planning a Database

Steps in Planning a Database

4  Decide what data fields are needed now and project future needs.

4  Define data fields and name them appropriately.

4  Establish guidelines for the contents of each field.

4  Enter data.

Planning the Database

Fields contain text or numeric data. In some databases, they can also contain pictures, computations, times, or dates.

The definition of fields is a critical part of planning the database. In order for the database to be useful, it must have all information necessary for solving a given problem (i.e., many useful and relevant fields).

Planning the Database

4  Fields should contain only one type of data in order to provide uniformity, make the database easy to use, produce consistent results from queries, and make the database more reliable.

4  It is best to subdivide fields for accuracy and ease-of-use. Example: Name (John Doe) could become Last Name (Doe) and First Name (John) or Size = 9lbs. 2oz. could be Pounds (9) Ounces(2).

Planning the Database

Naming fields is also important. Long, unrelated names should be avoided and replaced with short, concise, and easily understood titles. Examples: 4  “City in the USA” = City 4  “Things birds eat” = Diet 4  “Length of reptile” = Length

Planning the Database

After fields have been selected and appropriately named, it is essential to analyze the field’s contents and design applicable rules or guidelines for data entry. Without guidelines or predetermined ranges for data entry, searching and sorting these fields will produce inconsistent and inaccurate results.

Some Currently Available Database Packages

4  Dbase 4  Oracle 4  ClarisWorks 4  Microsoft Works for

Windows 4  Access

Database Structures

4  Hierarchical

4  Relational

4  Network

Hierarchical Databases

4  This is the simplest type of database. 4  The tree structure illustrates this concept.

Hierarchical Databases

4  Information is accessed from the top to the bottom (top-down).

4  Illustrates a parent-child relationship where each item relates only to the one above and below it.

4  Disadvantage – following the hierarchy is sometimes difficult, cumbersome, and time consuming.

Relational Database

4  Allows multiple associations using common fields in multiple databases.

4  Arranged in a two-dimensional table format.

4  Files are known as relations, fields are columns, and records are called rows.

4  Performs the following: joining, projection, and selection.

Relational Database

4  Used in libraries effectively

4  Users must define, create, and implement files. This is not automatically done by the relational database or database management system.

4  Disadvantage: there is no way to link fields in a practical manner. Explicit links are formed by relations (or files rather than specific fields contained within files).

Network Databases

4  These types of databases have a less rigid structures than the hierarchical model. They permit the use of pointers to establish the shortest path to specific information.

4  This model is well suited for transaction processing like those found in banking, inventory control, and airline reservation systems.

Network Databases

4  Good for standardized operations. 4  Disadvantage: Complex pointer

implementation makes modification involved, and requires care to keep established links from being lost.

4  When transactions are not predictable or stable, a relational database is a better model.

Products from a Database

After the database has been created and data entry has taken place, students or users can produce reports or lists that sort, extract, and summarize information from the database.

Sort Arrange in ascending or descending order.

Extract Produce a subset from the collection of information.

Summarize Total amounts or a count of items located.

Data Extraction – Arithmetic and Boolean Operators

= Equal to

< > Not equal

> Greater than

>= Greater than or equal

< Less than

<= Less than or equal

AND Include all items

OR Include either item

NOT Exclude item

Matching Database Functions with a Learning Task

Modified from (Table 11-1, pp.259) of Morrison and Lowther’s Integrating Computer Technology into the Classroom, 2ed.

Learning Task Database Function

Combine, Match, Sequence Match and Sort Information

Compare, Contrast, Discriminate, Relate

Sort, Analyze, Query

Classify, Identify, List Sort, Query Assemble, Report Report Customization

Advantages of Databases

4  Data collection, analysis, and manipulation.

4  Comparison, synthesis, and evaluation.

4  Relationships between data.

4  Arranging, organizing, and collecting data.

Applicability to many different types of problems involving:

Advantages of Databases

4  Fast, efficient data access and reporting. 4  Built-in search and retrieval functions. 4  Good for data integrated from many

sources. 4  Flexible, user-friendly formats for storing

the contents of fields.

Advantages of Databases

4  Reduce inconsistencies when users carefully define, enter, and verify data.

4  Cost-effective way to generate answers to questions related to information processing needs.

4  Save time when data must be located, updated, and retrieved.

Advantages of Databases

4  Maintains data integrity when there is a “few-to many relationship” i.e., only one or two people actually define and update the database, while many use the data contained therein.

4  Security is available through protected copies and passwords in many database packages.

4  Built-in wizards, templates, and imported data.

Disadvantages of Databases

4  Duplication or redundancy. 4  Difficulty evolving the database over time. 4  Difficulty building the database for

complex problems and applications. 4  Difficulty defining fields and establishing

guidelines for data entry.

Student Misconceptions About Databases

4  Queries and Filters are one in the same. 4  The most important thing to remember

about constructing a database is entering data appropriately.

4  Databases are not used for calculation.

Correcting Misconceptions about Databases

4 Queries and filters are one in the same Actually, these are different; queries are usually more specific, involve more steps, and utilize more data fields to select required criteria.

4 The most important thing to remember about constructing a database is entering data appropriately. This is good, but it is more important to plan the database well by specifying needed data and establishing firm guidelines for data entry.

Queries vs. Filters

4  Good situations for a setting a query: 3  Using more than one table for data

selection. 3  Performing calculations on selected record

values. 3  Viewing only some of the fields in a record.

4  Good situations for setting a filter: Viewing only a subset of records.

Disadvantages of Filters

4  Filters allow you to select criteria one field-at-a-time, and they are very restrictive (all criteria must be met before a record is displayed).

Queries

4  More powerful selection instrument, because you can use related tables.

4  You only display the fields you add to the query.

Correcting Misconceptions about Databases

4 Databases are not used for calculation. Although complex formulas and sophisticated computations are better served by other tools, you can create computed fields with numeric data fields and generate some statistical data (averages, minimum and maximum values, standard deviations, and grand totals) for reports.

4  Once data is entered, the database should be used to construct reports.

4  Difference between sorting and indexing.

4  Specifying data types.

Correcting Misconceptions about Databases

4 Once data is entered, the database should be used to construct reports. Data should be verified and validated before constructing reports.

4 Difference between sorting and indexing. Sorting has to do with the physical arrangement of data, while indexing deals only with the organization of the common key field.

Correcting Misconceptions about Databases

Difference between sorting and indexing.

Sorting Indexing

Physical arrangement based on a specified order. Example: arranging names alphabetically – As listed before Bs, etc…

Records appear based on how they are entered, but a unique key field contains an Identification number for each record that identifies its position. Example: Abraham, Jane, might be listed after Hinton, Bob, but the key field uses an ID number that appropriated sequences these names alphabetically.

Correcting Misconceptions about Databases

4 Specifying data types This is extremely important. If default data types (integer, character, fixed, etc.) are used, comparisons, calculations, and results will be inaccurate. Always specify the data’s type to avoid confusion and ensure correctness.

Correcting Misconceptions about Databases

References

Bitter, G., and Pierson, M. (2002). Using Technology in the Classroom. 5th ed. Allyn and Bacon: Boston. Morrison, G., and Lowther, D. (2002). Integrating Computer Technology into the Classroom. 2nd ed. Merrill Prentice Hall: New Jersey.

Summary

Electronic databases can save time and help user’s prepare, manipulate, organize, and disseminate data that answers questions and solves information processing problems. The database’s ability to compile, manipulate, and store large quantities of information in short time periods makes it a viable and useful tool in both education and industry.