Data, Information, and Knowledge Overview

Data usually refers to raw data/unprocessed data. Information is data that has been processed in such a way as to be meaningful. Information is data that has structure and context.

<p>Encryption is the conversion of data into a form that cannot be easily understood by unauthorised users</p> Signup and view all the answers

<p>Lookup check. A table of the three models would be stored. Data is entered into a cell with the rule. Data is compared to entries in the table. If data matches an entry it is allowed/lf data entered does not match any of the entries in the table it is rejected.</p> Signup and view all the answers

<p>Rule could be that price must match model number. If the model number is 1273C3 price must be $300. If the model number is 1273C6 price must be $400. If the model number is 1275C3 price must be $350. If the model number is 1275C6 price must be $450. If the model number is 1278C3 price must be $500. If the model number is 1278C6 price must be $600. Rule could be that memory must match model number. If model number ends in 3 memory must be 32. If model number ends in 6 memory must be 64.</p> Signup and view all the answers

<p>Data that does not change. It can be read without being written back to a file/not changed when written back. Limited amount of information in a static information source, because as soon as it is created it is difficult to have information added to it, Static data tends to go out of date quickly. Appropriate example such as a CD ROM contains static data.</p> Signup and view all the answers

<p>Read the text carefully to find/correct typographical errors/mistakes in grammar/style/spelling. Printing a copy is sometimes better than reading on screen, as it allows you to catch more visual errors. Read the essay out loud, as this will help you catch errors in grammar and sentence structure. Use a blank sheet of paper to cover up the lines below the one you are reading, to prevent you from skipping ahead of possible mistakes. Use the search function of the computer to find mistakes he is likely to make, such as 'it,' for instance, if he confuses 'its' and 'it's', 'there' for 'their' or 'they're'. Check separately for each kind of error he is likely to make, moving from the most to the least important. Read through once backwards, sentence by sentence. Read through again forward to be sure subjects and verbs agree.</p> Signup and view all the answers

<p>To be marked as a level of response: Level 3 (7-8 marks) Candidates will describe each check and give benefits and drawbacks of each check/consider different reasons for using each check. The issues raised will be justified. The information will be relevant, clear, organised and presented in a structured and coherent format. Specialist terms will be used accurately and appropriately. Level 2 (4-6 marks) Candidates will describe each check and give benefits and drawbacks of checks/consider different reasons for using each check although development of some of the points will be limited to benefits or drawbacks. For the most part the information will be relevant and presented in a structured and coherent format. Specialist terms will be used appropriately and for the most part correctly. Level 1 (1-3 marks) Candidates may only describe checks, and give basic reasons. Answers may be simplistic with little or no relevance. There will be little or no use of specialist terms. Level 0 Response with no valid content.</p> Signup and view all the answers

<p>Static information sources are carefully checked for accuracy, as once the data are used it is difficult to change. There is a limited amount of information in a static information source, as soon as it is created it is difficult to have information added to it. A dynamic data source can have information updated quite quickly. The data in a dynamic data source is usually up to date/static data tends to go out of date quickly. There can be many contributors to a dynamic data source such as a website, so the information can be inaccurate.</p> Signup and view all the answers

<p>Range check for the exam mark. No mark should be less than 10 or greater than 100. Lookup check for year. Years should match 12 or 13. Format check for date of birth. All dates of birth must be two digits followed by a slash followed by two digits followed by a slash followed by four digits. Consistency check on year with date of birth. The date of birth can be checked to see that the year the student is in corresponds to that.</p> Signup and view all the answers

<p>She could give questionnaires to students who walk to school using that particular road asking about their general health/number of days missed through illness, She could give questionnaires to students who walk to school using other roads asking about their general health/number of days missed through illness. She could interview students who walk to school using that particular road asking about their general health/number of days missed through illness, She could interview students who walk to school using other roads asking about their general health/number of days missed through illness. She could observe/keep a count of traffic coming down the busy road, She could observe the amount of traffic/keep a count of traffic coming down the other roads. She could use sensors to detect the flow of traffic going down the busy road, She could use sensors to detect the flow of traffic going down the other roads. She could give questionnaires to residents who live in that particular road asking about their general health, She could give questionnaires to residents who live in other roads asking about their general health. She could interview residents who live in that particular road asking about their general health, She could interview residents who live in other roads asking about their general health.</p> Signup and view all the answers

<p>Data gathering may be expensive as other companies may have to be hired to get it. It may involve having to purchase equipment such as data loggers/computers/printers. Compared to indirect data sources using direct data sources may be very expensive in preparing and carrying out the gathering of data. Costs can be incurred in producing the paper for questionnaires, It takes longer to gather data than to acquire data from an indirect data source. By the time the project is complete/all the data is collected the data may be out of date. The sample size may be small.</p> Signup and view all the answers

<p>In questionnaires and interviews the questions may not have been very clear and the respondents may have misunderstood them, so that the respondent thought they knew the answer Josefine wanted - resulting in similar answers from different respondents. Questions may have been open-ended allowing the respondent to produce answers which could not be quantified. In a multi-choice type question there may not have been a sufficient number of alternatives. The respondents selected for the study may not have been very representative. There is the possibility that Josefine may have made errors when collecting it. Josefine may have made errors when entering the collected data into the computer. If the data was collected automatically by sensors the computer/microprocessor may not have been set up properly to accurately interpret the readings.</p> Signup and view all the answers

<p>Speeds up data entry. Accuracy of entering data is increased. When data has been coded it makes it easier to use validation. Less storage space is required. The smaller the size of the database, the faster it will be to search and produce results.</p> Signup and view all the answers

<p>The code B does not give a clear idea of what shade of blue. The approximate age of the driver is too vague/too general and would be difficult to use in calculations/graphs. There may be many makes of car beginning with the same letter.</p> Signup and view all the answers

<p>Asymmetric encryption is often referred to as public key encryption, The public key is used to encrypt the data while, the corresponding private/secret key is used to decrypt the data. The public key is published to everyone, but the private key is kept secret. Anyone with a copy of the public key can encrypt information, but only the private key holder can read it. It is not possible to deduce the private key from the public key.</p> Signup and view all the answers

<p>Irrelevant information leads to poor quality information</p> Signup and view all the answers

<p>Encrypting a hard disk prevents viruses from deleting the information</p> Signup and view all the answers

<p>They are just a collection of text, numbers and symbols with no meaning. A possible context is that the data is about the student and represents: their family name, first name, student id, their latest maths mark and their date of birth.</p> Signup and view all the answers

<p>Length check on Workers ID number. Must be exactly 6 characters long. Lookup check on Department. Must be one of Foundry, Cold rolling, Tube production, Extrusion or Hot rolling. Range check on hourly rate. E.g. be between 50 and 65.</p> Signup and view all the answers

<p>Data consists of raw facts and figures</p> Signup and view all the answers

<p>Data on a web page that is updated from time to time is an example of dynamic data</p> Signup and view all the answers

<p>Verification is checking that data that has been/is being entered into a computer has been copied correctly from the data source. Validation is checking that the data entered is reasonable/sensible. Neither method checks that data is accurate/correct. Although verification helps to stop users from making mistakes when entering data it cannot check that the data was originally correct. Validation is needed because although the data might be copied correctly, the original data might be invalid. The date of birth might be in the form dd/mm/yyyy and the data might have been correctly copied as 1994/12/31 but this is not in the correct format, a format check would have picked this up. Common errors when copying data are transcription and transposition errors. Verification would pick up a transposition error but most validation checks (except a check digit) would not. Verification would pick up transcription errors but validation might not.</p> Signup and view all the answers

<p>Both involve checking that data has been entered correctly not that it is correct. Visual verification is visually checking the entered data against the source document. Double data entry is usually two people entering the data/entered (by the same person) twice (and each version compared against the other). Visual verification is carried out by a human/user/yourself. Double data entry - verification is carried out by the computer. Visual verification will enable the user to see mistakes if they have been made, while double data entry the computer will alert user to the fact that a mistake has been made and they decide which version has been copied correctly.</p> Signup and view all the answers

<p>A direct data source is a source where data is collected for a specific purpose or task. Examples of direct data sources are questionnaires or data logging. An indirect data source is when data is obtained from a third party not necessarily related to the current task. Direct data source. It gives us data that is often called 'original source data'. Questionnaires could be distributed amongst farmers and local people asking about the effects of pollution. Interviews could be carried out with farmers and local people asking about the effects of pollution. Indirect data source. Means data that was collected for a particular reason but is then used for another purpose. Could collect data from local government agencies which may have pollution data for the local area. Could collect data from local environment groups.</p> Signup and view all the answers

<p>This question to be marked as levels of response: Level 3 (7-8 marks) Candidates will discuss the importance of encoding data including the advantages and disadvantages. Candidates will explain the effectiveness of the main methods of coding in detail. The information will be relevant, clear, organised and presented in a structured and coherent format. There may be a reasoned conclusion/opinion. Specialist terms will be used correctly and appropriately. Level 2 (4-6 marks) Candidates will discuss the advantages and disadvantages of encoding data. Candidates will describe the main methods of encoding in detail. For the most part, the information will be relevant and presented in a structured and coherent format. There may be a conclusion/opinion. Specialist terms will be used appropriately and for the most part correctly. Level 1 (1-3 marks) Candidates will present advantages or disadvantages of encoding data. Candidates will describe at least one method of encoding in detail. There will be little or no use of specialist terms. Level 0 (0 marks) Response with no valid content.</p> Signup and view all the answers