Shared Flashcard Set

Details

research module 3
research module 3
61
Dentistry
Undergraduate 3
02/04/2015

Additional Dentistry Flashcards

 


 

Cards

Term
steps of research
Definition

ask a question/ identify problem

 

hypothesis-proposed answer to question

 

literature review

 

plan

 

research

Term
hypothesis
Definition

a proposed answer to question

 

should be stated in positive terms

 

ex: 2nd year DH students noted heavy plaque on the posterior teeth of 1st graders but less plaque on anterior of 1st graders.

 

hypothesis for this: six and seven year children brush anterior teeth for a longer period of time than posterior.

Term
null hypothesis
Definition

a statement about between 2 groups where there is no difference.

 

example:six and seven year old children showed no difference in the effectiveness of plaque removal with brand x toothbrush

Term
what is involved in the plan?
Definition

 who will participate?

 

who will gather data?

 

how will the data be gathered?

 

when will they gather data?

 

CALIBRATION MUST HAPPEN

Term
reliability
Definition
future studies can be replicated

consistent, stable

calibrated examiners
Term
validity
Definition
measures what it was intended to measure
Term
research pyramid most valid to least valid
Definition

systematic reviews  (secondary research)

 

randomized controlled studies

 

cohort studies

 

case series

 

case reports

 

ideas, editorial, opinions

 

animal research

 

in vitro (test tube) research

Term
what is the highest level of primary research?
Definition
randomized controlled double blind study
Term
interrater reliability
Definition
two or more examiners being in agreement with findings.
Term
Intrarater reliability
Definition
one examiner is consistent with himself
Term
when a population is limited is is said to have
Definition
parameters
Term
taking a portion of given population is known as
Definition
sampling
Term
what is more valid, small or large sampe
Definition
large sample is more valid
Term
pilot study
Definition

trial run

 

prepares for major study

Term
blind study
Definition
used to prevent research outcomes from being influenced by either the placebo effect or the observer bias
Term
random sampling
Definition

method of sampling that provides the most external validity or degree to which the results of study can be generalized to settings

 

-each member fo population has equal chance to be in study.

 

-prevents possibility of selection bias by researcher

Term
stratified sampling
Definition

subdivision of a population with similar characteristics (called strata)

 

random selections of two or more strata is another way of defining stratified sampling

Term
systematic sampling
Definition

selection using every (nth, or so many patients)

 

(example every 3rd person in the phone book)

Term
purposive (judgemental) sampling
Definition

could have bias

 

sample based upon personal judgement of those who would most represent population

Term
convenience sampling
Definition

group of individuals who are most readily available to be subjects

 

could have bias

Term
experimental group
Definition
the sample group in a study who recieves the experimental treatment or intervention
Term
control group
Definition

group in study who does not recieve treatment

 

placebo effect

 

provides baseline against which the effects of intervention on the experimental group can be measured.

Term
Independent Variable
Definition

what you give to the experimental group.

 

is controlled by experimenter

 

what is new or different

 

 

Term
dependent variable
Definition

it is what happens or not

 

depends on or is caused by independent variable

 

*it is the outcome variable of interest

 

*it is the effect of the independent variable (it happens second)

Term

example of variables:

 

the independent is in blue

 

the dependent is in red

Definition
patients with 7 mm pockets will recieve scaling and root planing and have brand X of antimicrobial applied to the 7mm pocket to see if pocket reduction occurs in 4 weeks.
Term
discrete data
Definition

 has one of a limited set of values and are counted only in whole numbers


example: hair color, gender, political preference

Term
continuous data
Definition

measurments made from a particular value within a defined range

 

(example: temperature, scores on a test)

things that change

 

Quantitative in nature

Term
nominal scales
Definition

measurement of names categories with no order

 

scores that cannot be heirarchally ordered

 

example: females placed in category a. males in category b. (one sex is not better or less than the other)

 

nominal scales are put into groups or classes

Term
ordinal scales
Definition

ranked order is used

 

example:

-stage I cancer

-stage II cancer

-stage III cancer

Stage IV cancer

 

other examples mohs hardness scale

Term
interval scales
Definition

have a common unit of measurement between each score, but no true zero

(example is temperature)


quantitative: mean, median, mode, standard deviation

Term
ratio scales
Definition

have equal intervals between the variables but there is a meaningful zero point.

 

example: height / weight

mass

length

time

plane angle

energy

electric charge

Term
two categories of discrete data
Definition

nominal scale

 

ordinal scale

Term
used to apply  info from sample for large population
Definition
inferential statistics
Term
4 ways to describe quatitative data
Definition

frequency-tabulating a group of scores

 

central tendency- scores tend to clump together

 

shape-whether scores pile up together (skewed vs. normal)

 

variability-how much scores are spread out

Term
descriptive statistics
Definition

used to describe and summarize data

 

objective: communication results without generalizing.

 

may use central tendency or measures of dispersement

Term
frequency
Definition

 list all scores

 

 put in ascending or decending order

 

slashes used

example

score                           frequency

10           /         1

 

this means 1 person got this question right out of 10 people

Term

grouped frequency

distribution

Definition

uses range

example: 10 intervals

 

if range is 96, highest, 27 lowest, then the range is 69

 

interval width= range/ # of intervals

Term
central tendency
Definition

scores are clumped together (bell curve)

 3 methods of computing

-mode

-median

-mean

Term
mode
Definition

most frequently occuring score

 

least reported measure of central tendency/ least stable

 

greatly influenced by a few scores

 

can be unimodal, bimodal, or multimodal

Term
median
Definition

 

the point that divides the distribution in half

 

the midpoint between all grades

 

if odd # of scores there is a difinitive median

 

if even # add two middle scores and divide by 2

 

whn distributions are skewed, the median represents central tendency.

 

 

Term
mean
Definition

average of all scores

 

take all scores/ how many scores are used

 

x=sum

N

 

 

Term
mean limitation
Definition

affected by extreme scores

 

can be pulled in either direction by very high or low very scores

Term
shape
Definition

 whether or not scores pile up at one end (normal vs skewed)

 

in normal mean, median , mode are equal

 

in skewed mean is pulled toward the tail, and median falls between mean and mode.

Term
positively skewed
Definition

mean is highest

 

median has middle value

 

mode is lowest (most frequent score)

 

more students had low scores indicating test too difficult

Term
negatively skewed
Definition

mode is highest

 

median is middle

 

mean is lowest

 

most students do well, but a few scores bring average down.

Term
variability
Definition

how spread out are scores

 

 use range= highest - lowest

 

example:

 

high score 100

low score 50

range = 50

Term
standard deviation
Definition

take square root of variance

 

SD is influenced by all values

 

large SD= large variability, or heterogeneity

 

small SD= small variability or homogeneity (scores cluster close to mean)

 

this measure is most appropriate for normal distributions

Term
correlation
Definition

measure of relation between 2 or more variables

 

look for clumping of dots on xy axis.  if lots of clumping, they are closely related.

 

 

 

mean and SD has been determined, correlations are used to see if one variable my be relatied to a variation in another variable

 

 

Term
positive correlation
Definition

2 variables increase

 

example of positive

 

students grades go up when they study alot

 

x axis up

y axis up

Term
negative correlation
Definition
one variable increases and the other decreases
Term
nonparametric stats
Definition

no parameters, parameter free

(have no idea how data will turn out)

Term
t-test
Definition

aka students test

 

compares mean of two groups (group A vs group B)

 

does experimental group have a higher mean?

Term
ANOVA
Definition

analysis of variance

 

allows comparison for 2  or more groups

 

compares variability within groups with variability between groups as a whole.

Term
chi squared tests
Definition

nonparametric inferential(draw a conclusionand make prediction) stat technique

 

most common test for significance of the relationship between categorical variables

 

degrees of freedom (2 choices)

Term
parametric studies
Definition
we know what we are testing for parameters are used
Term
confidence intervals
Definition

researchers can calculate the probability of statistics being correct.

 

researchers usually us a 95%-99% confidence interval.  this indicates the results will be wrong 5 times in 100.

Term
P values
Definition

p value states how likely it is that a study could have come to a false scientific conclusion.

 

calculated according to sample size, difference of means in control and experimental groups, and standard deviation of distribution.

 

acceptable p values will be less than .05% (the smaller number the more significant the study)

Term
type I alpha errors:
Definition
researchers rejects the null hypothesis
Term
type II beta errors
Definition
the researcher accepts the null hypothesis, but it is actually false.
Supporting users have an ad free experience!