in the application of statistical tests. The independent variable answers
the question What do I change?, the dependent variable answers the
question What do I observe? and the controlled variable answers the
question What do I keep the same?. A variable
LLC M Molecular weight Momentum per unit time N lb MLt2
M Mach number n Exponent, constant n Normal
direction m ft L n Manning roughness factor n Number of moles
N Rotation speed 1/sec 1/sec t 1 NPSH Net positive suction
head m ft L p Pressure Pa lb/ft2
form, then you will have a collection of written documents which
require analysis of the question answers. If the survey has been
completed by a researcher, then a more sophisticated method of data
collection may have occurred e.g. tallies and counts of r
Secondary data can be analysed using the same techniques as for
primary data. See the following section on statistical analysis for more
details. 22 23 Case study: Using secondary data to create a baseline
Baseline assessments refer to a number of headlin
wider survey. allowing a reduction in investment in CCTV?. The
respondent may wish to provide multiple answers to this question,
answering yes to having more community support officers, but
disagreeing with the reduction in investment for CCTV. See the se
confidence interval between two means). 28 29 Example Survey 1 finds
that economic activity stands at 49% using a sample of 1,000 residents.
Another sample is selected one year later. Survey 2 finds that 51% of
residents are economically active. In this c
requires sophisticated knowledge and practice. Clearly, to be experts in
their use, requires practice, but like any tool, the basic principle behind
its use can be understood and applied, by all. Furthermore, for those
who have no intention of actually us
who speak the com - munities language to assist where necessary.
What are the geographic restrictions? The geographic spread of the
population to be surveyed will determine the method used for
collecting your data. If you are surveying people from a parti
L2t 1 y Stokes stream function m3/sec ft3/sec L3t 1 w Angular
velocity rad/sec rad/sec t 1
Research Methods Handbook Introductory guide to research methods
for social research Stuart MacDonald & Nicola Headlam, CLES CLES 2 3
Centre for Local Economic Stra
far away from body, free stream T Total pressure J Static pressure Greek
Symbols a Angle, coefficient b Blade angle G Circulation
m2 ft2 L2t 1 u Vector operator 1/m 1/ft L1 g Specific weight N/m3
lb/ft3 ML2t 2 d Boundary layer thickness m ft L e Kinematic
baseline assessment. Further reading How official statistics are collected
has improved a lot in recent years, the neighbourhood statistics website
is very user-friendly and uses maps, graphs and tables for a wide range
of official statistics, presenting
respondents to add any categories that have been omitted; Ranking
scales these are most commonly used when trying to ascertain the
level of importance of a number of items. A list of choices are provided
and respondents are asked to put them in order (e.g
them and how you are going to organise the task. The following section
outlines some key considerations that need to be made before
embarking on a large-scale survey. Population A number of questions
about the proposed population for a survey need to be c
routinely in the information-storage industry for thickness
measurements (with nanoscale spatial resolution) of lubricant films, a
few nanometers thick, in rigid magnetic disks. References Bhushan, B.
1995. Handbook of Micro/Nanotribology, CRC Press, Boca
using a silicon nitride tip at a normal force of 300 nN for the
unlubricated and lubricated silicon samples. 25 20 15 10 5 0 Friction
Force (nN) Normal force = 300nN 0 10 20 30 40 50 60 70 80 90 100
Number of cycles Z-DOL/Si(100) Z-15/Si(100) Si(100) 3-20
different types of secondary information. Some of the most common
types are identified as follows: Official statistics - This refers to national
data sets relating to issues such as population, employment and
unemployment and businesses. Much of this info
access secondary data (as detailed above) for establishing and
updating baselines; develop baselines retrospectively. This entails
deciding key indicators and collecting data for a period of time in the
past (e.g. the start of a regeneration programme);
every question is measuring something, it is important for each to be
clear and precise. Your goal is for each respondent to inter - pret the
meaning of each survey question in exactly the same way. If your
respondents are not clear on what is being asked
population you are targeting. SurveyMonkey SurveyMonkey is an online
survey tool that enables people of all experience levels to create their
own surveys quickly and easily. It has an online survey designer, which
contains many questions and formats. It c
to a particular local authority officer role across the country, then a
postal or email survey would work best, as it is likely there will be over
350 in the population, geographically dispersed and literate. Pros Cons
Postal Can reach a large geographica
particular emphasis on quantitative survey methods.
http:/qb.soc.surrey.ac.uk/ A general introduction to the design of
questionnaires for survey research, University of Leeds
http:/www.leeds.ac.uk/iss/documentation/top/top2.pdf The Centre
for Applied Soci
confidence interval is affected by three factors. These are the sample
size, percentage and population size. Sample Size The larger your
sample, the more confident you can be that their answers truly reflect
the population. The relationship between the co
Total energy per unit mass J/kg ftlb/lbm L2t 2 E Total energy J ftlb or
Btu ML2t 2 E Modulus of leasticity Pa lb/ft2 ML1t 2 Eu Euler number
f Friction factor F Force N lb MLt2 Fr Froude number
FB Buoyant force N lb MLt2 g Acceleration of gravity m/sec2
how they are structured and analysed. In this section we focus on the
quantitative use of surveys, and in later sections we explore the more
qualitative use of survey methods. When should it be used? When you
need to generate primary data from a large num
understanding. Statistical analysis, through a range of statistical tests,
can give us a way to quantify the confidence we can have in our
inferences or conclusions. Statistical analysis should only be used where
there is a clear understanding of the reas
you may use and it is important to understand which you are using:
Cross-sectional surveys are used to gather information on a population
at a single point in time. An example of a crosssectional survey would
be a questionnaire that collects data on peopl
of members of a population from which members of a sample are then
selected. A sampling frame needs to be accurate, complete, up-to-date
and relevant to the purposes of the survey for which it is to be used.
Once you have an established sampling frame, de
http:/www.ocsi.org.uk/ Pros Cons Robust, accurate data enabling
comparison across time/area Health warnings around use of statistics
need to make sure of appropriateness in context Very credible and clear
picture can emerge when presented well Using only
members of a Chambers of Commerce in a particular location. Detailed
consideration of sampling needs to be made to ensure the validity of
your results, and the following issues need consideration: Who is the
respondent? The first thing you need to under -