 |
RMC811S-RESEARCH METHODS FOR NATURAL SCIENCES-2ND OPP- JULY 2025 |
|
|
1 Page 1 |
▲back to top |
nAmlBIA unlVERSITY
OF SCIEn CE Ano TECHn OLOGY
FACULTY OF HEALTH, NATURAL RESOURCES AND APPLIED SCIENCES
DEPARTMENT OF NATURAL RESOURCES SCIENCES
QUALIFICATION: BACHELOR OF NATURAL RESOURCES MANAGEMENT HONOURS
QUALIFICATION CODE: 08BNRH
COURSE CODE: RMC811S
LEVEL: 8
COURSE NAME: RESEARCHMETHODS FOR NATURAL
SCIENCES
DATE: JULY 2025
DURATION: 3 HOURS
MARKS: 150
SECOND OPPORTUNITY/SUPPLEMENTARY EXAMINATION QUESTION PAPER
EXAMINER(S) Dr Tendai Nzuma (Section A: Scientific Writing)
Dr Meed Mbidzo (Section B: Statistics)
MODERATOR: Prof M. Mwale
INSTRUCTIONS
1. Answer ALL the questions.
2. Write clearly and neatly.
3. Number the answers clearly.
PERMISSIBLEMATERIALS
1. Examination question paper
2. Answering book
3. Calculator
THIS QUESTION PAPER CONSISTS OF 8 PAGES (Excluding this front page)
|
|
2 Page 2 |
▲back to top |
QUESTION 1
SECTION A: SCIENTIFIC WRITING
[SO]
(20)
a) Define plagiarism and list three common types found in academic settings.
(6)
b) Describe how a student can avoid plagiarism when paraphrasing, summarising, and quoting.
(6)
c) Explain the importance of referencing and citation in scientific writing. Provide an example using
APA style (in-text and reference list).
(8)
QUESTION 2
(30)
a) Identify and explain four key functions of the Discussion section.
(8)
b) Using the result: "Compost increased maize height by 15 cm (p < 0.05)", write a model paragraph (12)
for a Discussion section.
c) Discuss how speculative language should be used cautiously in the Discussion. Provide examples. (10)
SECTION B: STATISTICS
QUESTION 3
What statistical procedure would you use for the following research questions and/or scenarios?
[100]
(10)
a) A researcher determined the presence of a specific intestinal parasite in each animal from a
(2)
random selection of mice of each of two species. You want to determine if there is a
relationship between mice species and occurrence of the parasite.
b) You take a sample of the weights of 20 male elephant tusks from Etosha National Park (ENP)
(2)
and a sample of 18 male elephant tusks from the Bwabwata National Park (BNP). You want to
test if there is a difference in tusk weights between elephants from ENP and BNP. Note: You
find that the tusk weights for BNP were not normally distributed and that there were significant
outliers in the data.
c) A researcher wants to determine if there is a relationship between soil moisture content and
(2)
nitrogen mineralization rates. They also want to predict mineralization rates at specific soil
moisture content levels.
d) Trace metals in drinking water affect the flavour and an unusually high concentration can pose (2)
a health hazard. Ten pairs of data were taken measuring zinc concentration in bottom water
and surface water (each pair of surface & bottom water samples are taken at the same
location). You want to test whether the data suggest significant differences in average zinc
concentration in bottom and surface water?
e) Habitat type and temperature are believed to affect insect diversity (using the Shannon Index). (2)
Habitat type is categorised into forest and grassland, while temperature has three levels: low,
medium and high. You want to assess the impact of habitat type and temperature on insect
diversity.
2
|
|
3 Page 3 |
▲back to top |
QUESTION 4
A park warden claims that the average weight of elephant tusks in his park is 50kg. A sample of five {14)
(5) tusks is taken and their weights are recorded. Use the SPSSoutput provided to answer the
questions that follow.
a) What statistical test would you use to investigate whether elephant tusk weight values from
(2)
the sample are different from the population mean?
b) State the null and alternative hypotheses for this investigation.
(2)
c) Is the assumption of normality met or violated? Explain and provide evidence for your answer. (2)
d) State whether the assumption of outliers is met or not (Explain and provide evidence for your (2)
answer.
e) Report on the descriptive statistics of the elephant tusk weights.
(3)
f) Determine whether the tusk weight values from the sample are different from the population
(3)
mean.
62.o>---------------------------
so.ol-------------===i===-----------
SB.of-----------
56.0 ,___ ________
_
54.0r-----------
s2.ol--------------+--------------
so.al---------------------------
Tuskweight in kg
Kolmogorov-Smirnova Shapiro-Wilk
Statistic df Sig. Statistic df Sig.
!Tusk weight in kg .182
5 .200· .964
*. This is a lower bound of the true significance.
5 .834
a. Lilliefors Significance Correction
Tusk weight in kg
N Mean Std. Deviation Std. Error Mean
5 55.660 4.0396
1.8065
3
|
|
4 Page 4 |
▲back to top |
Test Value = 50
Significance
Mean
t
df One-Sided p !Two-Sided p Difference
Tusk weight in 3.133 4 .018
kg
.035
5.6600
95% Confidence Interval
of the Difference
Lower Upper
.644 10.676
QUESTION 5
Ecologists count bird species in a degraded habitat before and after a restoration project. Use the
{15)
SPSSoutputs provided to answer the questions that follow.
a) What statistical procedure or test would you use to determine whether habitat restoration
(2)
significantly increased bird species richness?
b) What are the two main data assumptions of the statistical procedure/test mentioned in (a)?
(4)
c) Have the two data assumptions in (b) been met or violated? Explain in detail.
(4)
d) Report on the descriptive statistics and fully explain whether habitat restoration significantly
(5)
increased bird species richness.
Differencebeforeand afterrestorato1n
Difference before and
after restoration
Kolmogorov-Smirnova
Statistic df Sig.
.164
15 .200·
Shapiro-Wilk
Statistic df
.929
15
Sig.
.267
4
|
|
5 Page 5 |
▲back to top |
Pair 1
Mean N
Number of bird species 19.5333 15
after restoration
Number of bird species 13.9333 15
before restoration
Std. Error
Std. Deviation Mean
2.94877
.76137
2.05171
.52975
Paired Differences
95% Confidence
Interval of the
Std.
Std. Error Difference
Mean Deviation Mean Lower Upper t
df
Pair Number of bird species 5.6000C 2.50143 .64587 4.21476 6.9852LI8.671 14
1 after restoration -
Number of bird species
before restoration
Significance
One- ifwo-
Sided p Sided p
<.001 <.001
QUESTION 6
A researcher examines pollution levels in three different sections of a river (upstream, midstream,
(18)
and downstream) by measuring dissolved oxygen levels. Use the SPSSoutputs provided to answer
the questions that follow.
a) What procedure or test would you perform to assesswhether pollution levels differ among river (2)
sections?
b) Explain whether the two main data assumptions (normality and homogeneity of variances) of (5)
the statistical test mentioned in (a) have been met.
c) How would you deal with violations of normality of data?
(3)
d) Interpret the descriptive statistics.
(4)
e) Fully explain whether pollution levels differ significantly among river sections.
(4)
Dissolved Oxygen
(mg/L)
River Section
upstream
midstream
downstream
Kolmogorov-Smirnova
Statistic
df
.144
10
.114
10
.165
10
Sig.
. 200·
.200·
.200·
Shapiro-Wilk
Statistic df Sig.
.966 10 .855
.969 10 .884
.905 10 .249
5
|
|
6 Page 6 |
▲back to top |
9.oot---------==---------------------
8.00 >------
:::.
gC,
1.00-
c.,
cl s.oor------------
-.0 ,
>
0
,n 5.00 -----------------------------
111
ci
4.001--------------------~
J.oot---------------------------
upstream
midstream
River Section
downstream
Descriptives
Dissolved Oxygen (mg/L)
N Mean
upstream 10 7.8450
midstream 10 5.8740
downstream 10 4.1020
Total
30 5.9403
Std.
Deviation
.57270
.45051
.35411
1.61910
Std. Error
.18110
.14246
.11198
.29561
95% Confidence Interval for Mean
Lower Bound Upper Bound
Minimum
7.4353
8.2547
7.02
5.5517
6.1963
5.12
3.8487
4.3553
3.58
5.3358
6.5449
3.58
Maximum
8.93
6.53
4.52
8.93
Dissolved Oxygen (mg/L)
Based on Mean
Based on Median
Based on Median and with
adjusted df
Based on trimmed mean
Levene Statistic dfl
1.091
2
1.148
2
1.148
2
1.097
2
df2
27
27
24.127
27
Sig.
.350
.332
.334
.348
ANOVA
Dissolved Oxygen (mg/L)
Sum of Squares df
Between Groups 70.116
2
Within Groups
5.907
27
rTotal
76.023
29
Mean Square
35.058
.219
F
160.244
Sig.
<.001
Multiple Comparisons
Dependent Variable: Dissolved Oxygen (mg/L)
Tukey HSD
(I) River
Section
upstream
midstream
Mean
(J) River Section Difference (1-J)Std. Error Sig.
midstream
1.97100·
.20918 <.001
downstream 3.74300·
.20918 <.001
upstream
-1.97100*
.20918 <.001
downstream 1.77200·
.20918 <.001
95% Confidence
Interval·
Lower Upper
Bound Bound
1.4524 2.4896
3.2244 4.2616
-2.4896 -1.4524
1.2534 2.2906
6
|
|
7 Page 7 |
▲back to top |
downstream upstream
-3.74300·
midstream
-1.77200·
Games-Howell upstream
midstream
1.97100.
downstream 3.74300·
midstream upstream
-1.97100*
downstream 1.77200·
downstream upstream
-3.74300·
midstream
-1.77200*
*. The mean difference is significant at the 0.05 level.
.20918
.20918
.23042
.21293
.23042
.18121
.21293
.18121
<.001
<.001
<.001
<.001
<.001
<.001
<.001
<.001
-4.2616
-2.2906
1.3801
3.1899
-2.5619
1.3073
-4.2961
-2.2367
-3.2244
-1.2534
2.5619
4.2961
-1.3801
2.2367
-3.1899
-1.3073
QUESTION 7
(15)
a) What does it mean to have data that are non-parametric?
(3)
b) What are the two main drawbacks of non-parametric tests?
(4)
c) In an experimental design, what is a control group and why is it important?
(3)
d) What is the importance of controlling for confounding variables in an experimental design?
(3)
e) Define a simple random sample.
{2)
QUESTION 8
Suppose we want to investigate the relationship between the number of hours studied and the
(28)
marks obtained on an exam. A sample of 20 Research Methods students were randomly selected,
and the number of hours they studied, and their exam mark were recorded. Use the SPSSoutputs
provided to answer the questions that follow.
a) What procedure or statistical test would you perform to test the research hypothesis stated
{2)
above?
b) Describe the general relationship that exists between exam marks and time spent studying.
(4)
Provide evidence for your answer.
c) Did the data meet the assumption of homoscedasticity? Explain your answer.
(4)
d) Did the data meet the assumption of normality? Explain your answer.
{3)
e) Did the data meet the assumption of no significant outliers? Explain your answer.
{2)
f) What proportion of the variance in the response variable is explained by the predictor
(4)
variable? Explain fully.
g) Determine whether the regression model results in a statistically significantly better prediction (4)
of the dependent variable than if we just used the mean of the dependent variable. Provide
evidence for your explanation.
h) Compute a regression equation using the SPSSoutput provided to predict the exam mark a
(5)
student would obtain if they studied for 5 hours.
7
|
|
8 Page 8 |
▲back to top |
Scatter Plot of Exam Mark by Hours Studied
1001----------------------------------
801----------------------------------
I
60 - -------
I::E
.
I ---
-1•----
a
401----------------------------------
201----------------------------------
•
0
Hours Studied
Model Summaryb
Model
1
R
R Square
.989a
.979
Adjusted R
Square
.978
Std. Error of the
Estimate
1.622
a. Predictors: (Constant), Hours Studied
b. Dependent Variable: Exam Mark
Scallerplot
Dependent Variable: Exam Mark
Durbin-Watson
1.353
•
0
'iii
-5
oi
&.,,!
•
•
-~ 01------------------------------
1
•
•
•
!1 .11-------,.~--------------------------"-
0
•
•
.
&"'!
•
_,1----------~------------------- •
-2
_,
Regression Standardized Predicted Value
8
|
|
9 Page 9 |
▲back to top |
Normal P-P Plot of Regression Standardized Residual
Dependent Variable: Exam Mark
1.0~------------·
£n
0.,1-----------f------
uE:,
,:,
0.4 ,__ ____
,, _________
_
in
o.o-------------
0.0
02
0.6
O.B
1.0
Observed Cum Prob
Sum of
Model
Squares
1
Regression
2187.823
Residual
47.377
Total
2235.200
a. Dependent Variable: Exam Mark
b. Predictors: (Constant), Hours Studied
ANOVN
df
Mean Square
1 2187.823
18
2.632
19
F
831.220
Sig.
<.001b
Unstandardized
Coefficients
Coefficientsa
Standardized
Coefficients
Model
B
Std. Error
1
(Constant)
46.049
.913
Hours
5.683
.197
Studied
a. Dependent Variable: Exam Mark
Beta
.989
t
50.444
28.831
Sig.
<.001
<.001
95.0% Confidence
Interval for B
Lower
Upper
Bound
Bound
44.131
47.967
5.269
6.097
9