Data/Information
A school collects the following information about its students:
17, Cantrell, 82, 91, 88
The school then calculates that the student's average grade is 87%.
Which part is data and which part is information?
The individual values collected are data. The calculated 87% average is information because the data has been processed to give it meaning.
A manager receives a report containing the correct sales figures.
Which quality of information does this demonstrate?
Accuracy
A company uses one secret key to encrypt and decrypt its files.
What type of encryption is this?
Symmetric
A student enters a test score of:
147
The system only allows scores from 0–100.
What validation check is being used?
Range check
A company collects employee hours throughout the week and calculates wages every Friday.
What type of processing is being used?
Batch processing
A school wants to find out how satisfied its own students are with the school's cafeteria.
The school sends a questionnaire to 500 students and collects their responses.
Is this direct or indirect data?
Direct data
A school wants to identify students who are at risk of failing an examination.
The database contains every student's:
The records are complete.
However, the database contains no examination grades or attendance information.
Which characteristic of information is the biggest problem?
Relevance.
The information may be complete in terms of the fields that exist, but the information is not relevant to identifying students at risk of failing.
Explain the differences between asymmetric and symmetric encryption
answers may vary
What is the difference between validation and verification?
Validation = “Is the data reasonable/acceptable?”
Checks that data follows a set of rules before it is accepted.
Verification = “Was the data entered correctly?”
Checks that data matches the original source or was entered consistently.
A customer purchases an item from an online store.
Immediately after payment is confirmed, the item's stock quantity changes from 6 to 5.
What processing method is being used?
Online processing
A supermarket wants to determine which products its customers purchase most frequently.
It has two possible approaches:
Method A: Ask customers what products they usually purchase.
Method B: Use data from a random database online
Which method would provide direct data, and which would provide indirect data? Explain.
A school principal asks for:
"The number of students in Year 12 who were absent more than five times this term."
The IT department gives the principal a 200-page report containing the attendance records of every student in the school for the last five years.
The information in the report is completely accurate.
Identify TWO characteristics of information that could make this report unsuitable for the principal's purpose. Explain each.
Relevance: Most of the information does not relate to the specific question.
Level of detail: The report contains far more detail than is required.
Age could potentially also be relevant because the principal asked about the current term.
A customer visits an online banking website and enters their account details.
The connection uses TLS.
Explain why TLS is appropriate in this situation.
TLS helps protect data during client-server communication by encrypting the connection, making it much harder for intercepted data to be read by unauthorized parties
A customer enters:
ABC123
into a field requiring a six-digit numeric customer ID.
Identify TWO validation checks that could potentially detect this entry.
Answer:
A water company records customers' meter readings throughout the month.
At the end of the month, the readings are processed to calculate each customer's bill.
The company is considering changing to real-time processing so that each customer's bill is calculated immediately after every meter reading.
Explain why real-time processing would not necessarily be an improvement. Explain what type of processing would be most appropriate and why.
There is no need to calculate the customer's bill immediately after every meter reading because the bill is only required at the end of the billing period.
Batch processing is appropriate because the readings can be collected and processed together.
Changing to real-time processing could add unnecessary processing requirements without providing a significant benefit.
A school collects the following data for every student:
The principal wants to identify students who may need additional academic support.
Explain two different ways the school could process the data to produce useful information.
Possible answers include:
A company uses customer information to send promotional offers.
The database contains:
The data is completely accurate and up-to-date.
However, the company discovers that 40% of customer records do not contain an email address.
Evaluate the quality of this information.
The information has poor completeness because a significant proportion of records are missing an important field.
Although the available data is accurate and current, it may not be suitable for sending email promotions because the company does not have the required information for many customers.
A company needs to send highly confidential financial information from Head Office to a remote branch over the internet.
The IT department is considering two encryption methods:
The company has hundreds of branches, and each branch must be able to communicate securely with Head Office.
Question:
Which encryption method would be more difficult to manage if used by itself in this situation, and why? Explain one advantage and one disadvantage of the alternative method.
Symmetric encryption would be more difficult to manage because the secret encryption key must be securely shared between Head Office and each branch. As the number of branches increases, managing and distributing the keys becomes more complicated.
Asymmetric encryption avoids the same key-distribution problem because public keys can be distributed openly while private keys remain secret.
A company transfers 50,000 sales records from one system to another.
Before the transfer, the system calculates the total of a particular numeric field.
After the transfer, it calculates the total again.
The two totals are compared.
What verification method is being described?
Hash total
A supermarket uses an automatic stock-control system.
When a customer buys the last bottle of a particular drink:
Identify the processing method being used and explain why.
Online processing is being used.
The sale causes the stock database to be updated and an electronic order to be sent to the supplier.
A farmer wants to determine whether his crops require more water.
He can use:
Which source would be direct data and which would be indirect data?
Direct: Soil moisture readings from sensors in his own fields.
Indirect:
A clothing company wants to predict which products will be popular during the upcoming summer.
The manager receives a report based on:
Sales data from the previous 15 summers
The data is completely accurate and includes every sale.
However, fashion trends have changed significantly in the last three years.
Evaluate the suitability of this information for the manager's decision.
The information is accurate and complete, but its age may make it unsuitable for predicting current customer preferences.
Older sales data may not reflect current fashion trends, customer preferences, or market conditions.
The company could still use the historical data to identify long-term trends, but it should probably combine it with more recent information.
A company wants to protect information sent between its offices over a network.
The IT department is considering TLS/SSL and IPsec.
Why might IPsec be more appropriate for protecting communication at the network level, while TLS is commonly associated with protecting particular client-server communications?
TLS/SSL is commonly used to secure particular client-server communications, such as communication between a browser and a web server.
IPsec operates at the network level and can protect IP communications between devices/networks.
The choice depends on what communication needs to be protected and at what level.
A bank employee enters an account number.
The system checks that the account number contains the correct number of digits and that the final digit matches a calculated value based on the other digits.
What validation method is being used?
Check digit
A company processes customer orders using batch processing.
Every six hours:
The company wants to switch to online processing because customers are complaining that their orders are not immediately reflected in their accounts.
Give TWO reasons why online processing could be more appropriate and ONE possible disadvantage of making the change.
Advantages
Disadvantage