Running Head: Measurements in Scientific Experiments

Data Collection in Scientific Experiments
Johnaton McAdam; Leandro Caponong; Safee Bazmi;
Saif Allahabi
The City College of New York
Author Note
This paper was prepared for English 210, taught by Professor Susan Delamare.
Table of Contents
Measurements
Abstract 3
Introduction 4
Materials and Methods 5
List of Materials 5
Methods 6
Results 7
Conclusion and Discussion 9
References 10
Appendix 10
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Measurements
Abstract
Taking measurements and collecting data are integral parts of any lab or experiment. They help
form the foundation of the scientific method and without proper understanding of which, the
observations and analysis of an experiment are compromised. In this article, the authors tested a
variety of methods of taking measurements and gathering data including, using measuring tape to
measure circumference of a head, evaluating Pi using data tested in an Excel function, using the
measurement tools on Google maps, and determining density by measuring mass and volume of
an object. The concepts of certainty and error were also demonstrated by using toothpicks
arranged in a circular shape and compared to a circle formed by a measuring tape. Doing so
showed that because of their straight lines,the toothpicks gave only an approximate answer,
while the measuring tape that could be curved gave a more precise answer. Proper data collecting
is important to ensure understandability of the experiment, reliability of the results, and
reproducibility in future experiments.
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Measurements
Introduction
What is a measurement? More importantly how does one quantify a measurement? To answer
these questions, one must understand how instruments are used to quantity data. The evaluation
of data is used in many different fields and is a fundamental step in any experiment or analysis, if
it is not measurable then it cannot be tested (Hagan, T. L, 2014). Measurement is foundation of
any kind of scientific procedure and is statistically measured to find correlations within each
other to develop a standard. All measurements will have an error, which is defined by the
accuracy and precision of the data. When data being is evaluated it is group into two categories
accuracy and precision. The accuracy is how close the data is compared to a standard value and
precision is the difference in data points to the average value, low difference is a high precision
and high difference is low precision. Before any kind of data evaluation, a calibration must be
performed to set a standard for the measurement, which will determine the accuracy of the
instrument. When measuring data, a reliability test must be conducted to test for the same results
at different time intervals and this will ultimately determine if the instrument is reliable. The
results from the reliability test will be used to determine the validity of the results and determine
if there is enough evidence to support the function of the instrument (Hagan, T. L, 2014).
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Measurements
Materials and Methods
The purpose of this experiment is to gather data then interpret the data to calculate the unknown
quantiles in each experiment. Gathering data itself can be very sensitive. Depending on the
equipment one uses they can make a mistake. Especially when it comes to measuring items that
aren’t always perfectly shaped like a perfect rectangle or circle. Realistically shapes aren’t
always perfect. With a lot of architecture in the twenty-first century, shapes are more abstract.
However, they are not too abstract that the building doesn’t work. It’s not just buildings, but
other items as well; like furniture, or cars.
List of Materials
Digital Caliper
2 Circular Objects
Paper Fish
Wood block
Digital Balance
Ruler
Measuring Tape
Bench Timer
Meter Stick
500g Mass
Tooth Picks
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Measurements
Methods
Exercise 1: Measure the circumference of your head then record the value.
Exercise 2: Use the tape measure to the circumference of the circular objects and record the data.
Then use the data to estimate the value of Pi by inputting the data into excel and using the slope
as the value for pi.
Exercise 3: Use google map to find the circumference of a circular building and record the data
similar to exercise 2 and estimate the value of pi.
Exercise 4: Calculate the density of the wood using the volume and mass measurements from
the scale and measuring tools.
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Measurements
Results
From the experiment the measurements that were recorded showed that measured values had
some deviations from the standard values. For example in the measurement of π three circular
objects were all used with crude measuring instruments such as tooth pics, measuring tape and
google maps. As expected the tooth picks produced the greatest uncertainty in the calculations
because in order to measure π a shape that is approximately close to circle was constructed
around the objects then each tooth pick was counted then multiplied by their length to get the
circumference. Lastly it was divided by its diameter and that gave the estimated value of π.
Similar the same procedure was done using google maps to measure a circular landscape, this
method produced the second highest value away from the standard value of π. The reason for
these variations is due to the instruments that were used, the instruments were not calibrated and
it was very crude since it did not provide any safety from human errors. The final experiment
involved the uncertainty calculation of the density using a ruler to measure the volume of the
wooden block with a given mass. The ruler as a uncertainty of 0.25 and because of that the
density should be within a range of ± the uncertainty of 0.25.
Measurements of Pi of 3 Circular Objects
Pi Estimate 1: 2.93
Pi Estimate 2: 3
Pi Estimate 3: 3.26
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Measurements
Figure 1: Shows the average value for pi, based on the circumference of various circular objects
and their diameter, which is represented by the slope.
Error Propagation of measurements
p = m/v (Density, g/cm ) (1) 3
Density of the wood
0.502 g/cm3
Uncertainty of the Measurements equation
(2)
For rulers the Δx = 0.25
wr = √(0.502 * 0.25) = 0.125 2
Uncertainty of the density measurement
0.502 ± 0.125 g/cm3
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Measurements
Conclusion and Discussion
Measurement is a foundation of any scientific procedure. But in modern times one can’t use tools
to measure everything, and if one does, then there are definitely gonna be some things that are
inaccurately measured. Moreover, if one does use there inaccurate measurements to do anything
they will be unsuccessful in it. When tools won’t measure the size of these products that’s when
one depends on higher math skills. They make it easier to find measurements of things that you
can’t easily use a tool to measure. Higher math skills are needed.
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Measurements
References
Hagan, T. L. (2014). Measurements in Quantitative Research: How to Select and Report on
Research Instruments. Oncology Nursing Forum, 41(4), 431–433. https://doi-org.ccnyproxy1.libr.ccny.cuny.edu/10.1188/14.ONF.431-433
Appendix
Table of Figures
1. Calculation of Pi based on the slope
List of Equations
1. Density
2. Kline-McClintock equation/ Measurement Uncertainty
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