Assessment criteria HL (total 28 marks)
A: Introduction
Achievement
level
Descriptor
0
There is no introduction or the background research presented is not made relevant to the experimental
hypothesis. The aim of the study is not stated. No hypotheses are stated.
1–3
Background theories and / or studies are identified but are limited in number, not well explained and / or not
highly relevant to the hypotheses. The aim of the study is clearly stated. The experimental and / or null
hypotheses are stated but are unclear or not operationalized. The prediction made in the experimental
hypothesis is not clearly justified by the background studies and / or theories.
4–5
Background theories and / or studies are adequately explained and highly relevant to the hypotheses. The aim
of the study is clearly stated. The experimental and null hypotheses are appropriately stated and
operationalized. The prediction made in the experimental hypothesis is justified by the background studies and
/ or theories.
The focus is on relevant background theories and / or studies, that is, those which are directly relevant to the candidate’s
hypotheses. As for “adequately explained” it should be interpreted in terms of explaining the aim, procedure and findings of the
background study. Candidates may perhaps add some details of sample or statistics in the original study but this is not a
requirement. Since most candidates have not read the original articles moderators should not expect a detailed account in line
with those found in research articles but rather relevant details which can lead directly towards the candidate’s own hypotheses.
B: Method: Design
Achievement
level
Descriptor
0
The independent variable and dependent variable are not accurately identified. No appropriate experimental
design is identified. There is no evidence of appropriate application of ethical guidelines, for example, there is
no evidence that informed consent was obtained from participants or their parents.
1
The independent variable and dependent variable are accurately identified but are not operationalized. The
experimental design is appropriate to the aim of the research but its selection has not been appropriately
justified. There is clear indication and documentation of how ethical guidelines were followed.
2
The independent and dependent variable are accurately identified and operationalized. The experimental
design is appropriate to the aim and its use is appropriately justified. There is clear indication and
documentation of how ethical guidelines were followed.
Moderators should refer to the information on "Ethical considerations". Experimental design (such as independent design or
repeated measures) must be identified and justified to gain full marks in criterion B.
C: Method: Participants
Achievement
level
Descriptor
0
No relevant characteristics of the participants are identified. No relevant sampling technique is identified or
the sampling method is incorrectly identified. The target population has not been identified.
1
Some characteristics of the participants are identified but not all are relevant. Some relevant participant
characteristics have been omitted. The sample is selected using an appropriate method but the use of this
method is not explained. The target population has been identified and it's appropriate.
2
Relevant characteristics of the participants are identified. The sample is selected using an appropriate method
and the use of this method is explained. The target population has been identified and is appropriate.
Relevant characteristics of the participants could be age range, sex, nationality, whether or not they are psychology students, or
characteristics that are important in the experiment such as the participants in a Stroop experiment not suffering from colour
blindness. All of these characteristics could be seen as relevant. Some candidates will also mention the type of school (public or
private). This is acceptable but it is not a requirement and candidates should not be penalized for not addressing this. In the past,
some candidates have mentioned socio-economic status but many do not and this is not a requirement. In IB schools with
students from many socio-economic groups it would not be possible to make a statement about socio-economic status and there
may be ethical issues involved in this also. Moderators should take into consideration that most participants in the experiments
are fellow students and moderators should use their judgment about what would be reasonable to expect as relevant
characteristics of the sample in an experiment of this kind.
An identification of the ‘target population’ from which the sample is taken is required. In most cases it would be the total student
population of the candidate’s school or parts thereof, for example, all students in the IB department. Moderators should note that
where the target population is not identified, but all other criteria for two marks are met, one mark should be awarded.
The assessment criteria refer to selection of an appropriate sampling method and explanation of its use. This can be understood as
‘justified’ or that candidates can simply explain how they sampled according to the chosen sampling method. Both ways are
acceptable.
D: Method: Procedure
Achievement
level
Descriptor
0
No relevant procedural information is included. The information provided does not allow replication. There
are no details of how the ethical guidelines were applied.
1
The procedural information is relevant but not clearly described so that the study is not easily replicable.
Details of how the ethical guidelines were applied are included. Necessary materials have not been included
and referenced in the appendices.
2
The procedural information is relevant and clearly described, so that the study is easily replicable. Details of
how ethical guidelines were applied are included. Necessary materials have been included and referenced in
the appendices.
Moderators should refer to the information on "Ethical considerations". It is sufficient for candidates to make a list of relevant
material in the materials section before the procedure and to make a reference to those materials in the appendices. In that case
there is no need to reference them again in the procedure section. If the requirements of criterion D are met satisfactorily in either
way, full marks should be awarded.
E: Results: Descriptive
Achievement
level
Descriptor
0
There are no results or the results are irrelevant to the stated hypotheses of the candidate's experimental study.
Relevant descriptive statistics have not been applied to the data. There is no graphing of data.
1
Results are stated and accurate and reflect the hypotheses of the research. Descriptive statistics (one measure of
central tendency and one measure of dispersion) are applied to the data, but their use is not explained. The
graph of results is not accurate, is unclear or is not sufficiently related to the hypotheses of the study. Results
are not presented in both words and tabular form.
2
Results are clearly stated and accurate and reflect the hypotheses of the research. Appropriate descriptive
statistics (one measure of central tendency and one measure of dispersion) are applied to the data and their use
is explained. The graph of results is accurate, clear and directly relevant to the hypotheses of the study. Results
are presented in both words and tabular form.
The assessment criteria state that descriptive statistics (one measure of central tendency or one measure of dispersion) are applied
to the data. However, it may be that candidates have nominal data. In this case descriptive statistics could be percentages or totals
and it would be impossible to use a measure of dispersion. Candidates should not be penalized for not including a measure of
dispersion when the data is nominal.
The guide states that the use of descriptive statistics should be explained. This could be interpreted as ‘justified’ with reference to
levels of measurement of the data or an explanation of how the descriptive statistics were applied to the data. Candidates should
not be penalized if they do not refer to levels of measurement of data in their explanation of the descriptive statistics.
A clear graph and a clear table must be included in this section to obtain full marks. If the graph and table are not properly
labeled then they are not clear. If the graph and / or table do not have a title but are clear and relevant to the hypotheses of the
study, one mark should be awarded.
F: Results: Inferential
Achievement
level
Descriptor
0
No appropriate inferential statistical test has been applied.
1
An appropriate inferential statistical test has been chosen, but no properly applied.
2
An appropriate inferential statistical test has been chosen and explicitly justified. Results of the inferential
statistical test are not complete or may be poorly stated.
3
An appropriate inferential statistical test has been chosen and explicitly justified. Results of the inferential
statistical test are accurately stated. The null hypothesis has been accepted or rejected appropriately according
to the results of the statistical test. A statement of statistical significance is appropriate and clear.
1.
Does the hypothesis predict difference or correlation?
2.
At what level of measurement are the data?
3.
Is the design related or unrelated?
However, not all statistics books mention the level of measurement of data as a justification and so candidates should not be
penalized for stating that the experiment investigated a difference and then mentioning the design. Points 1 and 3 are always
mentioned in the books. Candidates must show a basic sense of the use of statistics and not a detailed knowledge of a particular
statistical procedure.
G: Discussion
Achievement
level
Descriptor
0
There is no discussion section, or the discussion of the results is irrelevant to the hypotheses.
1–2
Discussion of the results is very superficial. The findings of the candidate's experimental study are not
compared to those of the study being replicated. Limitations of the design and procedure are not accurately
identified. No modifications are suggested and there is no conclusion.
3-5
Discussion of the results is not well developed or is incomplete (for example, discussion of either the
descriptive or inferential statistics is missing). The findings of the candidate's experimental study are
mentioned with reference to relevant background studies and / or theories. Some relevant limitations of the
design and procedure have been identified, but a rigorous analysis of method is not achieved. Some
modifications are suggested. The conclusion is appropriate.
6-8
Discussion of results is well developed and complete (for example, descriptive and inferential statistics are
discussed). The findings of the candidate's experimental study are discussed with reference to relevant
background studies and/or theories. Limitations of the design and procedure are highly relevant and have been
rigorously analysed. Modifications are suggested and ideas for further research are mentioned. The conclusion
is appropriate.
Discussion of results should include reference to background research (theories and / or studies) and the results of the statistical
calculations. Candidates who have discussed their results in the results section instead of here should not be penalized. The
important thing is that the candidate’s own statistical calculations are discussed in the report in a relevant manner.
Candidates should compare their own results to the research (theories / studies) mentioned in the introduction and with regard to
the details they have mentioned there. Moderators should moderate the candidate’s own explanation in the introduction rather
than looking for something which would be expected in a research article.
The assessment criteria require that ‘modifications are suggested and ideas for further research are mentioned’ to obtain marks in
the top range. If candidates suggest modifications of hypothetical future research, this should be accepted. If candidates suggest
relevant modifications of their study and then give suggestions for research that could be conducted in the same area, this is also
acceptable.
Criterion H: Citation of sources
Achievement
level
Descriptor
0
Sources are not cited within the report. No references are provided, or no standard citation method is used.
1
The references are incomplete or a standard citation method is not used consistently.
2
All in-text citations and references are provided. A standard citation method is used consistently throughout
the body of the report and in the references section.
All references must be provided in the introduction and in the discussion section. A standard reference method should be used
consistently (for example, APA or MLA but candidates should not be penalized for not using APA). If candidates do not apply
secondary citation correctly in the report but use a standard reference method in their bibliography they should lose only one
mark in criterion H.
Criterion I: Report format
Achievement
level
Descriptor
0
The report is not within the word limit of 1,500–2,000 words. Required sections of the report are missing, for
example, no abstract is included. Appendices are missing or incomplete.
1
The report is within the word limit of 1,500–2,000 words. The report is complete but not in the required
format. Appendices are not labelled appropriately and / or are not referenced in the body of the report. The
abstract is poorly written and does not include a summary overview of the candidate's experimental study,
including the results.
2
The report is within the word limit of 1,500–2,000 words. The report is complete and in the required format.
Appendices are labelled appropriately and are referenced in the body of the report. The abstract is clearly
written and includes a summary overview of the candidate's experimental study, including the results.
The format of the abstract should be aim, procedure, findings / conclusion. All elements should be present to obtain full marks.
Calculation of the statistical test (descriptive statistics and inferential statistics) should be included in the appendices. Candidates
may use calculators or online calculators but the calculation should be documented in the appendices, for example with a
screenshot if an online calculator is used. If this is not the case it will affect the marks awarded in criterion I.