2003 answers

Comments and answers to PMB 2003 – Computer Studies

Multi choice answers

The process of deleting permanently all the records in a database is called?
This process is called deleting. When we use Microsoft Access we just delete something – There is no other step to take after that. An old DBMS called dBase IV had a "pack" command that was used to remove all records in a table that had been "marked for deletion".
Database terms we should know include: creating a table, inserting new records (adding new lines to the middle of a table) , appending records (adding new records to the bottom of a table) , creating a query, creating a report, creating a switchboard, modifying the structure of a table, forms, searching, editing, indexing.
In Logo programming, PD stands for?
“Pen Down”
Other Logo terms: Pen Up, Pen Down, Right Turn, Left Turn, Forward, Back, Hide Turtle, Show Turtle, Clear Screen, Repeat
Repeat 4 [forward 10 Right Turn 90 ]
forward 100 Repeat 3 [Right Turn 90 Forward 50]
Repeat 3 [forward 34 Right Turn 120]
In a spreadsheet what does label mean
Non-numeric data. We use labels for headings or text in a worksheet.
Know also: Function, Formulae, Charts, Formatting cells, Cutting, Copying and Pasting, Naming cells, cell addresses, cell ranges, absolute addresses (like $A$3 ), relative addresses (like A3).
What does the term “inference engine” mean?
Expert systems are made up of two parts, the inference engine and the knowledge base. The inference engine is the part of an expert system that is going to do reasoning based upon the information in the knowledgebase.
You should also know about natural language systems and perception systems.
In word processing, the features that can be changed by character formatting commands are ____
font, size and style
Other word processing terms to know : save, save as, page setup, print preview, print, title bar, menu bar, tool bar, status line, search, search and replace, headers and footers, margins for page, indenting, alignment (left, right, centred, justified) formatting (characters, paragraphs) bullets and numbering, inserting things (pictures, clipart, other documents such as a spreadsheet from Excel), cut, copy and paste, spelling check…
What is a special purpose computer?
A special purpose computer is one that is used for one purpose only. It is different to a general purpose computer. Examples of special purpose computers are (i) controller for air-conditioning system (ii) ATM machine (iii) computer in your car engine (iv) computer in washing machine (v) TV remote control (vi) electronic burglar alarm. A general purpose computer is a (i) PC (ii) mini computer (iii) mainframe (iv) microcomputer (v) notebook (vi) PDA
What does DATE (03, 09, 02) represent?
This represent the date 2^nd September 1903. This is a tricky question that is very unfair to ask students. There are many different formulae and it is unreasonable to expect students to memorise all of them. There was no correct answer for this in the 2003 PMB examination. The closest answer was 2^nd September 2003.
What are some common internet services?
Some services that might be offered by an ISP include (i) e-mail (ii) web hosting (iii) internet access (iv) website design assistance (v) FTP file transfer help.
Services are things that a the ISP will be able to do for us. Protocols are different to services. FTP and TCP/IP are protocols. Protocols are rules that are used by the computer industry when they design hardware and software. For instance, the rules for communication must be followed by all the modem manufacturers – otherwise it would not be possible to communicate between computers using different modems.
What is a smart card?
A credit card sized piece of plastic that includes a microchip which holds information about and for the owner. A lot of information can be stored inside the microchip. Other types of card to know about include credit cards and credit cards.
Sound synthesizing means mixing different signals to produce various sounds.
Hardware used to do this includes (i) sound card (ii) microphone (iii) ADC (iv) DAC (v) speaker (vi) a microchip processor on the soundcard

Section B

Name two editing modes in word processing.
(i) insert mode (ii) overtype mode. In insert mode text we type is inserted into our document at the cursor position. In overtype mode new text replaces text to the right of the cursor.
Note that there are several ways of viewing text. For instance we can view text in web layout, normal and page layout format. We should make sure that we know the purpose of each menu item in the word processor menu bar.
Name any two aspects to control the way slides are presented by a computer.
We can control how slides are presented by using
(i) automatic timing
(ii) by having buttons on the screen that we can click on to move to the next slide. The name of a presentation package that we use is PowerPoint. We might use PowerPoint to present information at a meeting. Presentation packages are often used by business people and sometimes by teachers in schools or lecturers in universities. PowerPoint applications are good for simple presentations, but not good for a lot of detail. A screen can not hold much information and so it is mainly used for presenting the main points of a presentation.
Give two examples of crimes associated with computers.
(i) Writing virus programs that are used to alter the data stored on a persons computer.
(ii) Gaining access to a computer without the permission of the owner of the computer.
Which two edit commands transfer a block of text into the clipboard?
(i) Cut (ii) Paste
Cut will transfer a selected block of text to a section of computer memory called the clipboard. The selected text is automatically deleted from the source document when text is cut.
Copy will copy a selected block of text to the clipboard. The source document remains unchanged after the copy operation has been completed. Other editing methods to be considered include using : spelling checker, grammar checker, thesaurus, inserting a file, using search and replace.
State any two paragraph formatting features.
(i) alignment (ii) line spacing
Text in a paragraph can be left aligned, right aligned, centred justified. The line spacing for a selected paragraph can be changed. The left and right indents can also be changed. The indent for the first line can be different to the indent for the rest of the paragraph. It is also possible to change the spacing between different paragraphs.
Give the term which measures the speed of the following.
(i) printer. We measure the speed of a printer using cps (characters per second) or we can also use ppm (pages per minute). There are two ways of describing the speed of a printer…
(ii) CPU. The speed of a CPU is sometimes measured using MHz. This is actually the frequency of the processor, and NOT the speed of the processor. MIPs are used for speed (million instructions per second) and also teraflops are used. Speed of a CPU is found by running a benchmark test, not by looking at the frequency of the processor.
What do the following acronyms stand for?
(i) MBC/1. This stands for matchbox computer.
(ii) e-mail. This stands for electronic mail.
There are many acronyms to learn in computing. Many acronyms have multiple meanings. It is advisable to learn the acronyms at the end of your textbook. Note that MBC could not be found in the “One Look” computer dictionary on the internet, indicating that the term is not used anymore and is otherwise not used as an acronym for computing anymore. There is a list of acronyms at www.brunei-bay.com. Look under Computing / Student Resources / General.
State two areas where simulation is used.
(i) Flight simulation. Pilots can practice emergency procedures and other normal flying operations using a simulator. This helps to ensure that the pilot will know what to do if there is an emergency since they will have already practiced the correct procedures.
(ii) Gaming. Games like tomb raider and counterstrike simulate reality. The user plays as if they were in a real world, with the benefit that they can die many times instead of only once like in the real world.
Simulators are used a lot in design work. Models are made that are tested before the real thing is build. We can build a model of an intersection for a road system and see how it works. If the model works fine then we can build the real thing.
What do the following terms mean?
(i) hard copy: This is a printed copy produced by a computer on a printer.
(ii) hardware: The physical parts of a computer system – things that can be touched. A keyboard is an example of hardware. A printer is also hardware. A computer program is software. Information and data in a computer system is software – everything else is hardware!
List any two components inside a system unit.
(i) motherboard
(ii) power supply
The main components of a system unit include the hardware for the central processing unit (processor and memory), bus hardware (motherboard), IO interfaces for connecting the CPU to peripherals and a power supply. The system unit might contain secondary storage devices such as a disk drive, CD-ROM, CD-RW, graphics adapter, internal modem and one or more of many other “add-ins”.
Give one example for each of the following.
(i) relational operator
some relational operators are > < <> >= <=
(ii) logical operator
three logical operators are AND OR NOT
Give two examples of high level languages
(i) Visual Basic (ii) COBOL
High level languages are programming languages are used to make computer programs. The instructions that the programmer writes are “English Like”. Before a high level program will work it needs to be converted into instructions that can be used as input to a processor. This means converting high level instructions into machine code. The process most often used for converting high level programs into machine code is called compiling. Other terms you might like to learn about include (i)interpreter, (ii) syntax error, (iii) semantic error, (iv) linking, (v) dynamic link library (DLL).
Besides the arrow keys name tow other cursor controlled keys found in a typical keyboard.
(i) Page Up (ii) Page Down
Others include (iii) Home (iv) End
Note that these keys are controlled by software. It is possible (and easy) to program the cursor control keys to do anything we like. We could program the End key to move the cursor to the end of our document instead of to move the cursor to the end of a line in our text if we though that would be more useful for people using the program that we wrote. A cursor is also controlled by combinations of keys. The Alt and Shift keys are often combined with other keys to make it easy for the user to control the cursor.
What type of device is used in the following?
(i) to produce a hard copy of a building plan
a plotter could be used to print a house plan.
(ii) to transfer pictures form a magazine to a printer
a scanner can be used to digitize an image that can then be input into a computer.
There are different types of plotter and also different types of scanner. Flatbed scanners and plotters are commonly used with PC’s. However, a commercial enterprise is more likely to use a drum plotter since it is able to draw on large pieces of paper. Hand held scanners are not used so much these days as they are not as good as flatbed scanners.
Name the two types of programming errors.
(i) syntax errors
(ii) semantic errors
syntax errors are spelling mistakes we make when programming source code in a high level programming language. Semantic errors are mistakes that we made in our flow charts and algorithms when we designed the program. These design errors then end up as errors in the code of our program. An example of a semantic error might be to use the formula Area = base x height to work out the area of a triangle. We find semantic errors at “runtime”. This means we usually detect semantic errors when our program produces unexpected output.

Section C

This section references diagrams. The answers below will only make sense if you have a copy of the 2003 paper to look at.

1. The diagram shows a typical word processing window.

a. State the functions of A and E
(i) A is for creating a new word processing document
(ii) E is for adding bullets to a list in our document.

b. Which labeled feature should be used to create a hanging indent
B is used for hanging indents

c. The diagram below shows a Print Setup dialog box. Which lettered options should be used for the following tasks?

i. To print a block of text selected by the user – G

ii. To print the best picture quality – K

iii. To print only pages 2, 4 and 8 - H

d. How could the page orientation be changed?
There are two ways of doing this. The page orientation for printing can be changed by selecting the Printer properties. However, the preferred way to set the page to landscape is to go to the Page Setup dialog box – this is different to the Print dialog box!

2. A school organized a walkathon to collect funds for the purchase of computers. The principal asked Cikgu Kamal to manage the amount of money collected by the various groups. Cikgu Kamal used a spreadsheet application package.

a. Cikgu Kamal wanted to know the lowest amount and the average amount collected for the walkathon. Write down the formula that automatically calculates

i. Lowest amount =min(C6:C11)

ii. Average =average(C6:C11)

b. Referring to the spreadsheet above. Provide answers to the following statements

i. The formula used to show the present date in cell C3? =now()

ii. The cell address of another cell whose content changes when the value 120 is entered in cell C8? C13

c. The amount collected by various groups is shown in the form of a chart. Describe briefly the steps necessary to produce the chart shown in the diagram.
The range B6:C11 is selected. The icon for creating charts is then clicked. The pie chart type is chosen and then the heading for the chart is selected and changed to “Amount Collected”. When all the necessary properties of the chart have been set then we can click OK to place the chart on our worksheet.

d. Explain how the ‘$’ sign can be made to appear automatically against each of the amounts collected.
The range C6:C13 is selected. Then Format / Cells / Currency is selected. We can decide on the number of decimal places for the formatted numbers and then click OK.

3. The diagram below shows part of a customer database for a mobile phone company. The Easycard field shows whether a customer subscribes to the Easycard service.

a. What data type is used for the following fields?

i. Postcode: text or character

ii. DOB: date

b. Referring to the above diagram, explain briefly the function of the icon labeled A.
The symbol displayed is used to append a new line to the bottom of the database table.

c. The company wants to list out all female subscribers. Write down the instructions to produce these details.
There are several ways to answer this question. One way is to use the filter option. To do this we should click on any ‘F’ value in the Sex column of the database table. We would then click on the filter icon. The females in the table will be displayed and the males hidden from view.
We could make a query that selects only the female students. We could do this using the QBE interface or by entering an SQL command. The SQL would look something like this…
Select * from Customer where Sex = “F”

d. The company decides to add another field called ‘Year of Registration’ to enable the company to know the number of customers registered in that year.

i. Describe briefly how the extra field can be added to the database.
We can click on the ‘design’ icon at the top of the screen when the table is shown. Then we can add the details of the new field to the end of the table structure. We should then save the modified structure before using the table to enter data again.

ii. Write down a query instruction that can list Easycard customers who registered in 2003.
Select * from Customer where [year of registration] = 2003

4. Peope in Brunei Darussalam can communicate with people in other countries through the internet.

a. Name the two internet service providers in Brunei Darussalam
(i) DST (ii) Brunet

b. Name the device to connect a computer to the internet
modem

c. Referring to the diagram, what is A and what is its other use?
A is a communication link of some type.
In Brunei, the technology used is likely to be a telephone line. The telephone line is dual purpose. It can be used for telephone conversations and for transmitting/receiving computer data.

d. One company in Brunei Darussalam decides to set up a network connecting all of its computers in the building. Name the type of network used.
A local area network (LAN) will be used.

e. The network is also connected to the internet. The company also uses some of the services available through the internet. Name the services that best fit the descriptions below.

i. To transfer money from one account to another.
(i) EFT (electronic funds transfer), (ii) EFTPOS (electronic funds transfer at point of sale) , (iii) EDI (electronic data interchange) , (iv) online banking – any of these are correct.

ii. To order goods
(i) e-mail (ii) e-commerce (iii) EDI

iii. To have discussions with people in different places
(i) Net meeting, (ii) teleconferencing, (iii) net to phone, (iv) chat rooms (v) messenger services. There are many technologies used for connecting people so they can communicate together in real time.

5. The computer is a useful tool but it also causes a lot of problems or hazards to our lives.

a. Computers are electronic devices. Electronic interference is likely to happen when two or more electronic devices are placed near to each other.
Give two examples of electronic interference.
(i) A network cable might not transmit data very accurately if it runs near to an electric motor such as an air conditioning unit. (ii) A mobile phone can interfere with the controls of an aeroplane. This is why mobile phones must be switched off when we go on an trip.

b. Give two reasons why computers are sometimes considered environmentally unfriendly.
(i) It takes a lot of valuable resources to make a single computer. (ii) Computers are not biodegradable. Computers are “thrown away” within a short time. What to do with thousands of tons of old computer equipment is a problem. Computers contain small amounts of dangerous material such as heavy metals. These are poisonous to people. If computers are not disposed of properly then these metals will make people unwell.

c. Computers can affect ones health when used for a long period of time. Identify and list down two examples of health problems related to the use of computers.
(i) RSI (repetitive strain injury). This problem occurs when keyboard operators have to work for long hours without suitable rest. (ii) Problems related to poor environmental conditions. Eye strain, muscle strains and head aches can occur because the furniture is not ergonometric, the lighting is poor, ventilation is poor, printers are noisy and so on.

d. The computer-related problems can be avoided by taking some preventative measures. Name any two such measures.
(i) Create a good working environment that includes the use of well designed work station, good ventilation and good lighting. (ii) Put in place people procedures that ensure that workers are given rests and are not doing the same task over and over again.

Section C part Two

Each question in this section is worth 10 marks. The answers you make for this section determine how good your grade is going to be. It is important to be able to create an answer that is (i) complete (ii) accurate (iii) well constructed. A question worth 10 marks should have at least 10 clearly identified points made. the following is one possible answer that might get good marks. Remember that there are many ways of making answers for this type of question!

Question: Give positive uses of computers by students and teachers

Students can learn ICT skills by using the computers at their school.
Any student leaving school and going either to continue study or else to go to work should have "office automation" skills. These skills are needed by students hoping to get a job.

Students can use the internet as a resource
The internet has a lot of useful information on it. Student use the online dictionary and other resources as well as their textbook. This extra resource makes learning more interesting and more valuable. Projects can be made that are much more interesting and useful than the projects that were made before computers were used.

Teachers can use the internet as a resource
There are many sites available on the internet that provide material that teachers can use for teaching. it is easy for a teacher to download worksheets and tests that have been created by other teachers.

Students can learn using a LAN.
Students can learn using CAL (computer assisted learning) software. The teacher can set up lessons for students and then monitor individual progress easily.

Teachers can communicate more easily
Teachers can communicate with students and other teachers using e-mail, video conferencing and so on. This ensures that there is better communication and a bette learning experience for students.

Students can learn at home

Comments and answers to PMB 2003 – Computer Studies

Multi choice answers

The process of deleting permanently all the records in a database is called?
This process is called deleting. When we use Microsoft Access we just delete something – There is no other step to take after that.
Other database functions that we should know about include: creating a table, inserting new records (adding new lines to the middle of a table) , appending records (adding new records to the bottom of a table) , creating a query, creating a report, creating a switchboard, modifying the structure of a table, forms, searching, editing, indexing.
In Logo programming, PD stands for?
“Pen Down”
Other things to know about LOGO include: Pen Up, Pen Down, Right Turn, Left Turn, Forward, Back, Hide Turtle, Show Turtle, Clear Screen, Repeat
Repeat 4 [forward 10 Right Turn 90 ]
forward 100 Repeat 3 [Right Turn 90 Forward 50]
Repeat 3 [forward 34 Right Turn 120]
In a spreadsheet what does label mean
Non-numeric data. We use labels for headings or text in a worksheet.
Functions, Formulae, Charts, Formatting cells, Cutting, Copying and Pasting, Naming cells, cell addresses, cell ranges, absolute addresses (like $A$3 )
What does the term “inference engine” mean?
Expert systems are made up of two parts, the inference engine and the knowledge base.
You should also know about natural language systems and perception systems.
In word processing, the features that can be changed by character formatting commands are ____
font, size and style
Terms to know for word processing include : save, save as, page setup, print preview, print, title bar, menu bar, tool bar, status line, search, search and replace, headers and footers, margins for page, indenting, alignment (left, right, centred, justified) formatting (characters, paragraphs) bullets and numbering, inserting things (pictures, clipart, other documents such as a spreadsheet from Excel), cut, copy and paste, spelling check…
What is a special purpose computer?
A special purpose computer is one that is used for one purpose only. It is different to a general purpose computer. Examples of special purpose computers are (i) controller for air-conditioning system (ii) ATM machine (iii) computer in your car engine (iv) computer in washing machine (v) TV remote control (vi) electronic burglar alarm. A general purpose computer is a (i) PC (ii) mini computer (iii) mainframe (iv) microcomputer (v) notebook (vi) PDA
What does DATE (03, 09, 02) represent?
This represent the date 2^nd September 1903. This is a tricky question that is very unfair to ask students. There are many different formulae and it is unreasonable to expect students to memorise all of them. There was no correct answer for this in the 2003 PMB examination. The closest answer was 2^nd September 2003.
What are some common internet services?
Some services that might be offered by an ISP include (i) e-mail (ii) web hosting (iii) internet access (iv) website design assistance (v) FTP file transfer help.
Services are things that a the ISP will be able to do for us. Protocols are different to services. FTP and TCP/IP are protocols. Protocols are rules that are used by the computer industry when they design hardware and software. For instance, the rules for communication must be followed by all the modem manufacturers – otherwise it would not be possible to communicate between computers using different modems.
What is a smart card?
A credit card sized piece of plastic that includes a microchip which holds information. A lot of information can be stored inside the microchip. Other types of card to know about include credit cards and debit cards.
Sound synthesizing means mixing different signals to produce various sounds.
Hardware used to do this includes (i) sound card (ii) microphone (iii) ADC (iv) DAC (v) speaker (vi) microchip processor on the soundcard

Section B

Name two editing modes in word processing.
(i) insert mode (ii) overtype mode. In insert mode text we type is inserted into our document at the cursor position. In overtype mode new text replaces text to the right of the cursor. Note that there are several ways of viewing text. For instance we can view text in web layout, normal and page layout format. We should make sure that we know the purpose of each menu item in the word processor menu bar.
Name any two aspects to control the way slides are presented by a computer.
We can control how slides are presented by using
(i) automatic timing
(ii) by having buttons on the screen that we can click on to move to the next slide. The name of a presentation package that we use is PowerPoint. We might use PowerPoint to present information at a meeting. Presentation packages are often used by business people and sometimes by teachers in schools or lecturers in universities. PowerPoint applications are good for simple presentations, but not good for a lot of detail. A screen can not hold much information and so it is mainly used for presenting the main points of a presentation.
Give two examples of crimes associated with computers.
(i) Writing virus programs that are used to alter the data stored on a persons computer.
(ii) Gaining access to a computer without the permission of the owner of the computer.
Which two edit commands transfer a block of text into the clipboard?
(i) Cut (ii) Paste
Cut will transfer a selected block of text to a section of computer memory called the clipboard. The selected text is automatically deleted from the source document when text is cut.
Copy will copy a selected block of text to the clipboard. The source document remains unchanged after the copy operation has been completed. Other editing methods to be considered include using : spelling checker, grammar checker, thesaurus, inserting a file, using search and replace.
State any two paragraph formatting features.
(i) alignment (ii) line spacing
Text in a paragraph can be left aligned, right aligned, centred justified. The line spacing for a selected paragraph can be changed. The left and right indents can also be changed. The indent for the first line can be different to the indent for the rest of the paragraph. It is also possible to change the spacing between different paragraphs.
Give the term which measures the speed of the following.
(i) printer. We measure the speed of a printer using cps (characters per second) or we can also use ppm (pages per minute). There are two ways of describing the speed of a printer…
(ii) CPU. The speed of a CPU is sometimes measured using Mhz. This is actually the frequency of the processor, and NOT the speed of the processor. MIPs are used for speed (million instructions per second) and also teraflops are used. Speed of a CPU is found by running a benchmark test, not by looking at the frequency of the processor.
What do the following acronyms stand for?
(i) MBC/1. This stands for matchbox computer.
(ii) e-mail. This stands for electronic mail.
There are many acronyms to learn in computing. Many acronyms have multiple meanings. It is advisable to learn the acronyms at the end of your textbook. Note that MBC could not be found in the “One Look” computer dictionary on the internet, indicating that the term is not used anymore and is otherwise not used as an acronym for computing anymore. There is a list of acronyms at www.brunei-bay.com. Look under Computing / Student Resources / General.
State two areas where simulation is used.
(i) Flight simulation. Pilots can practice emergency procedures and other normal flying operations using a simulator. This helps to ensure that the pilot will know what to do if there is an emergency since they will have already practiced the correct procedures.
(ii) Gaming. Games like tomb raider and counterstrike simulate reality. The user plays as if they were in a real world, with the benefit that they can die many times instead of only once like in the real world.
Simulators are used a lot in design work. Models are made that are tested before the real thing is build. We can build a model of an intersection for a road system and see how it works. If the model works fine then we can build the real thing.
What do the following terms mean?
(i) hard copy: This is a printed copy produced by a computer on a printer.
(ii) hardware: The physical parts of a computer system – things that can be touched. A keyboard is an example of hardware. A printer is also hardware. A computer program is software. Information and data in a computer system is software – everything else is hardware!
List any two components inside a system unit.
(i) motherboard
(ii) power supply
The main components of a system unit include the hardware for the central processing unit (processor and memory), bus hardware (motherboard), IO interfaces for connecting the CPU to peripherals and a power supply. The system unit might contain secondary storage devices such as a disk drive, CD-ROM, CD-RW, graphics adapter, internal modem and one or more of many other “add-ins”.
Give one example for each of the following.
(i) relational operator
some relational operators are > < <> >= <=
(ii) logical operator
three logical operators are AND OR NOT
Give two examples of high level languages
(i) Visual Basic (ii) COBOL
High level languages are programming languages are used to make computer programs. The instructions that the programmer writes are “English Like”. Before a high level program will work it needs to be converted into instructions that can be used as input to a processor. This means converting high level instructions into machine code. The process most often used for converting high level programs into machine code is called compiling. Other terms you might like to learn about include (i)interpreter, (ii) syntax error, (iii) semantic error, (iv) linking, (v) dynamic link library (DLL).
Besides the arrow keys name tow other cursor controlled keys found in a typical keyboard.
(i) Page Up (ii) Page Down
Others include (iii) Home (iv) End
Note that these keys are controlled by software. It is possible (and easy) to program the cursor control keys to do anything we like. We could program the End key to move the cursor to the end of our document instead of to move the cursor to the end of a line in our text if we though that would be more useful for people using the program that we wrote. A cursor is also controlled by combinations of keys. The Alt and Shift keys are often combined with other keys to make it easy for the user to control the cursor.
What type of device is used in the following?
(i) to produce a hard copy of a building plan
a plotter could be used to print a house plan.
(ii) to transfer pictures form a magazine to a printer
a scanner can be used to digitize an image that can then be input into a computer.
There are different types of plotter and also different types of scanner. Flatbed scanners and plotters are commonly used with PC’s. However, a commercial enterprise is more likely to use a drum plotter since it is able to draw on large pieces of paper. Hand held scanners are not used so much these days as they are not as good as flatbed scanners.
Name the two types of programming errors.
(i) syntax errors
(ii) semantic errors
syntax errors are spelling mistakes we make when programming source code in a high level programming language. Semantic errors are mistakes that we made in our flow charts and algorithms when we designed the program. These design errors then end up as errors in the code of our program. An example of a semantic error might be to use the formula Area = base x height to work out the area of a triangle. We find semantic errors at “runtime”. This means we usually detect semantic errors when our program produces unexpected output.