Computer Science Level One Reports

2012

STANDARD REPORT
91074 Demonstrate understanding of basic concepts from computer science

COMMENTARY
Every effort was made to ensure pages of reports are read in the intended order. This could not be guaranteed where a candidate did not staple their report as required in the specifications.

Every effort was made to ensure that a candidate’s identity was not known to the marker. This was not possible where candidates had written their names on their report.

Every effort was made to ensure the security of candidate reports by requiring candidates to write their NSN on the top right hand side of each page of the report. Candidates who did not write their NSN as required created an unnecessary risk.

Candidates whose report was printed in a font size less than the specified font size and whose submission size approached the maximum number of pages were disadvantaged by this decision

Candidates, who did not acknowledge copied text at the place in the report where the text was used, disadvantaged themselves by that decision.

Candidates who provided code or screen shots that were too small were disadvantaged if it cannot be read it cannot be marked.

Candidates who used the work they did to produce a specific outcome, for example a sorting process, and reflected upon this in their report generally demonstrated understanding. Candidates whose reports used concepts relevant to the specific context of their own experience and used examples drawn from the specific context of their own experience generally demonstrated understanding.

Candidates who relied upon a thesaurus to substitute words into text did not demonstrate understanding. Reports that were completely generic often did not convince the marker that the understanding demonstrated was actually the candidate’s own. Sections of reports completed as class activities often did not convince the marker that the understanding was the candidates own. Candidates who relied heavily on information provided from model answers or commercial resources inserted into templates generally failed to demonstrate understanding. Reports that were constructed as answers to closed questions often did not convince markers that the understanding was the candidate’s own. Candidates who relied heavily upon the reproduction of teacher notes or material from commercial sources generally failed to demonstrate understanding. Candidates who wrote in their own voice using their own words about things they had done and understood generally demonstrated understanding.

In producing the Algorithm section of the report, candidates who provided photos of their own sort process coupled with an explanation of what they had done often succeeded. 

Candidates, who described first iteration through loop and then said “and so on”, did not describe the whole process in their example. Clear distinctions need to drawn between sort algorithms and search algorithm. Candidates appear to consider sorting and searching as the only algorithms possible.

Candidates were often loose in their use of  terminology, “a programme is a collection of algorithms’, informal instructions is pseudocode…” Informal instructions imply assumed knowledge and programmes are written in a formal programming language. Candidates need to describe/explain personal examples to demonstrate their understanding of these concepts.

Candidates using programmes for comparison of costs for sorting algorithms need to reference the source, and give explanation/conclusions in their own words to demonstrate their understanding.
When using graphs the axes must be determined, as must the data source. An explanation of how the data was produced and an interpretation of its representation is also required. The graph by itself is simply an image. If colour is used for reference in graphs, then work should be printed in colour.

When sorting an absolute minimum of five items is required. Both small and large numbers should be used for comparison of sorting algorithms. When a sort is, being described a clear description of context and process is required. Candidates who used better examples of a high-level programming language than HTML were often advantaged. Some candidates put forward the incorrect assumption that Scratch is a low-level language.

Candidates who understood the difference between usability and familiarity were advantaged. These candidates were often able to consider the subtle differences between user friendly, usability, ease of use, user experience.

ACHIEVEMENT
Candidates who were awarded Achievement demonstrated the required understanding. They commonly:
• described the roles of algorithms, programmes and informal instructions
• described an algorithm for a task in their own words, showing understanding of steps in an algorithm
• discussed the concept of cost for a specific algorithm of a particular size
• described some characteristics of programming languages such as syntax, input and output statements, control structures, storage, with reference to their own experience and examples
• described roles of levels of languages with reference to humans and computers
• mentioned high level language, low level language and compiler in correct context
• described the usability of the interface of a computer or electronic system showing understanding of the user interface and not just features of the device or programme.

NOT ACHIEVED
Candidates awarded Not Achieved commonly:
• lacked detail in their discussion of the concepts of algorithms, programmes and informal instructions
• were unable to describe an algorithm for a specific task in their own words
• paraphrased text without understanding
• were confused in their description of the programming languages NCEA Technology Level 1
• described features and functions of devices or programmes without discussing the user interface.
• described only one or two of the concepts.

ACHIEVEMENT WITH MERIT 
Candidates awarded Achievement with Merit commonly:
• explained in their own words the distinctions between algorithms, programmes and informal instructions
• generated their own description of an algorithm
• used their own work to show understanding of the sequential, conditional and iterative structures in an algorithm
• discussed with in-depth understanding the cost of an algorithm
• explained in detail and in their own words the importance of the roles of high and low level programming languages
• explained the need for translation between high and low level programming languages
• explained how different factors of a user interface for a device or programme in their own experience contributed to the usability of the interface, and not just the usefulness of the programme or device.

ACHIEVEMENT WITH EXCELLENCE 
Candidates awarded Achievement with Excellence commonly:
• compared and contrasted the concepts of algorithms, programmes and informal instructions, in their own words and examples
• compared the cost of two different iterative algorithms in terms of steps required for the same problem of the same size of input data
• compared and contrasted the levels of programming languages and the different ways that high level languages are translated into machine languages, relating accurately to their own work
• compared and contrasted related interfaces to illustrate how different factors of an interface contribute to its usability
• used personalised explanations and contextually sound language
• explained in depth and detail with own words giving student voice to demonstrate comprehensive understanding.

2011

91074 Demonstrate understanding of basic concepts from computer science
COMMENTARY 

Candidates whose work was presented in a variety of font sizes and styles were not advantaged. Candidates who produced well formatted and well structured documents were advantaged as formatting and structure do make a contribution to demonstration of understanding. In particular, small screen shots, text too small to read, and graphs with unlabeled axes did not contribute to a demonstration of understanding.

Candidates who clearly demonstrated understanding of basic concepts from computer science wrote in their own voice, providing evidence from their own work and experience to support any factual or referenced material.

Candidates who applied sourced material in a specific context made good use of the sources. Where knowledge identified from a source was applied in the specific context, it was obvious that the candidate had demonstrated understanding.

Candidates whose reports relied heavily on NZQA exemplars, internet sites, commercially available resources or supplied notes did not often clearly demonstrate their own understanding and often earned Not Achieved grades.

Candidates with templated reports often did not demonstrate understanding. In particular, reports which consisted of answers with no context demonstrated no understanding.

Candidates whose reports did not adequately distinguish between a supplied question and the candidate’s response often did not demonstrate understanding. Reports that reproduced supplied or sourced material without relating the identified knowledge to a specific context often did not demonstrate understanding. For example, a common task for algorithms was the quicksort. Candidates who explained by means of their own experiment often demonstrated understanding. Candidates who simply reproduced an explanation from a website often found understanding difficult to demonstrate.

Some candidate reports contained a gap between the evidence presented and a genuine demonstration of understanding. Some reports did not distinguish adequately between an algorithm and a program, making relatively simplistic claims. For example, candidates claimed, ‘a program is a lot of algorithms together’, without reference to a program’s characteristics: precise language, rules of syntax, and coding structures. Also, some candidates presented tables of numbers ‘relating’ to algorithm costs without reference to how the numbers were produced. Often in this type of report, descriptions had been reproduced without any reference to specific context. This reproduction reflected the candidate’s lack of understanding of the basic concepts.

In considering Human Computer interfaces, some candidates confused functionality of devices with usability. Candidates who were clear on the difference between how easy a device is to use (usability) and what the device can do (functionality) presented evidence relating to usability and avoided presenting evidence relating only to function. Candidates who presented evidence relating to mainly to functionality often did not demonstrate the required understanding.

ACHIEVEMENT
Candidates who were awarded Achievement for this standard demonstrated the required skills and knowledge. They commonly:
• demonstrated some understanding of the basic concepts from computer science
• described key characteristics of algorithms, programs, and informal instructions
• described an algorithm for a task, showing some understanding for the kinds of steps that can be in an algorithm
• attempted to determine the cost of an algorithm of a particular size
• described the role and characteristics of programming languages
• described the roles of high-level and low-level languages and the need for a compiler
• described the role of a user interface and factors that contributed to its usability.

NOT ACHIEVED
Candidates who were awarded Not Achieved for this standard lacked some or all of the skills and knowledge required for the award of Achievement. They commonly:
• did not demonstrate understanding of basic concepts from computer science
• described only one or two of the three required concepts
• lacked detail in their descriptions
• attempted to paraphrase without understanding
• did not provide evidence for all of the standard’s requirement when using a template.

ACHIEVEMENT WITH MERIT
In addition to the skills and knowledge required for the award of Achievement, candidates who were awarded Achievement with Merit commonly:
• demonstrated in-depth understanding of basic concepts from computer science
• explained how algorithms are distinct from related concepts such as programs and informal instructions
• showed understanding of the way steps in an algorithm for a task can be combined in sequential, conditional, and iterative structures
• determined the cost of an iterative algorithm for a problem of size n
• explained how the characteristics of programming languages are important for their roles
• explained the need for programs to translate between high-level and low-level languages
• explained how different factors of a user interface contributed to its usability.

ACHIEVEMENT WITH EXCELLENCE
In addition to the skills and knowledge required for the award of Achievement with Merit, candidates who were awarded Achievement with Excellence commonly:
• demonstrated comprehensive understanding of basic concepts from computer science
• articulated their understanding in their own words and from personal experience
• compared and contrasted the concepts of algorithms, programs, and informal instructions
• determined and compared the costs of two different algorithms for the same problem of size n
• compared and contrasted high-level and low-level languages
• explained the different ways in which high-level programming languages are translated into machine language
• discussed how different factors of a user interface contributed to its usability by comparing and contrasting related interfaces.

Comment/Reflecttion
One thing that I am finding interesting reading these report is the literacy word has not come up. It is more around Candidate has not shown understanding or lacked detail. These external standards count towards literacy credits.