Six steps to an effective
literature search
Information skills for PhD
students: 1
Jane Falconer
Improving health worldwide
www.lshtm.ac.uk
Hemorrhagic Dengue Fever Warning by Augapfel
http://www.flickr.com/photos/qilin/2937406223/
Reproduced under a Creative Commons Licence
HAPPY RAMADHAN [Mobarak Alaikom Al Shahar]
by Radiant Guy
http://www.flickr.com/photos/lexrex/249840249/
Reproduced under a Creative Commons Licence
pg. 2
Six steps to an effective literature search:
1.
2.
3.
4.
5.
6
• Scoping your search topic
• Choosing the resources to search
• Choosing your search terms
• Compiling your search strategy and running your search
• Finding the full text
• Managing your information
pg. 2
1.
2.
3.
4.
5.
6
• Scoping your search topic
• Choosing the resources to search
• Choosing your search terms
• Compiling your search strategy and running your search
• Finding the full text
• Managing your information
pg. 3
What do you want the literature
to tell you?
Ask questions…
Question x4 by Mike Coghlan
http://www.flickr.com/photos/mikecogh/4256561918/
Reproduced under a Creative Commons Licence
Type of study
Situation
Outcome
Comparison
is ityou
What
youwant
The
want
is Systematic
itto
context
you
tocompare
doareintrying
which
review
whatWhat
is itDo
about
the
with these
interventions?
topeople?
do?
the Controlled
study took trial
place.
population
you
are
Maybe
Compare
you
want
Includes
with
to
placebo?
givegeographical
interested
in
which
Cohort
study
them
a drug,
ask
location
their
or type of
makes
them
different
Compare
with
no
Economic
opinion,
update
health
policy…
service
from the intervention?
general
evaluation
organisation
public? This part is optional, you
Intervention
People
PICOST framework
Qualitative
do not need to have a
comparison etc.
Type of study
Situation
Outcome
Comparison
Ramadan
I do
not
have
AnyAny
a impact on
Nutritional
Pregnant
women
comparison
so this will
baby
Breastfeeding
remainwomen
blank for now
Impact
on
foetus
Nursing babies
Nutritional
impact
on
Foetus
breastfeeding mother
Nutritional impact on
pregnant woman
Intervention
People
Impact of Ramadan on pregnancy
and breastfeeding
Exercise 1
Page 4
pg. 4
1.
2.
3.
4.
5.
6
• Scoping your search topic
• Choosing the resources to search
• Choosing your search terms
• Compiling your search strategy and running your search
• Finding the full text
• Managing your information
Doesn’t PubMed or GoogleScholar
have all the information I need?
Google
Scholar
Google
Scholar
PubMed
Google
Scholar
Google
Scholar
Google
Scholar
All academic peer-reviewed
literature
All biomedical academic
peer-reviewed literature
Google
Scholar
Google
Scholar
Google
Scholar
Doesn’t PubMed contain all of
Embase?
Only 15% of titles
are found in all
three databases
Global Health
3235
380
306
1520
1533
1586
1411
Medline
Embase
Figures reproduced with permission from
www.cabi.org. Global health: solving local problems
with global information. Figure 1. Online at:
http://www.cabi.org/Uploads/ProductAdmin/a832dacf
-4063-4669-9c1f-4023856fa767.pdf
So, how many databases should I
search?
Background
search
• 1 or 2
MSc
dissertation
(primary
research)
MSc
dissertation
(secondary
research)
• 3 or 4
• 4 or 5
PhD
• As many as are
practicable
This is a general guideline only. The number of resources to
search is dependent on the scope of your search
Exercise 2
Page 4
pg. 7
1.
2.
3.
4.
5.
6
• Scoping your search topic
• Choosing the resources to search
• Choosing your search terms
• Compiling your search strategy and running your search
• Finding the full text
• Managing your information
pg. 7
Identifying your concepts
What subjects must items you find address in
order to answer your search question?
What is the nutritional impact of
Ramadan on nursing mothers and their
babies?
Hemorrhagic Dengue Fever Warning by Augapfel
http://www.flickr.com/photos/qilin/2937406223/
Reproduced under a Creative Commons Licence
HAPPY RAMADHAN [Mobarak Alaikom Al Shahar]
by Radiant Guy
http://www.flickr.com/photos/lexrex/249840249/
Reproduced under a Creative Commons Licence
Exercise 3
Page 8
pg. 7
Using synonyms
US and UK spellings
(behavior and
behaviour)
US and UK
terminology
(physiotherapist and
physical therapist)
Abbreviations
(acquired
immunodeficiency
syndrome and AIDS)
Different word
endings
(climate and climatic)
Generic and trade
names of drugs
( Fluoxetine and
Prozac)
Diseases and
disease vectors
(dengue and aedes)
What is the nutritional impact
of Ramadan on nursing
mothers?
nutrition
• Diet
• nutrients
nursing
mothers
Ramadan
• fasting
•
•
•
•
Breastfeeding
Breastfed
Breast milk
lactation
pg. 7
Exercise 4
Page 9
What are subject headings?
Indexing terms added to each article by the database
compilers NOT the author
Terms are chosen from a pre-defined list, updated annually
Terms are specific to each database
Can help make subject searches more comprehensive
Example from Medline®
Rakicioğlu N. et al. The effect of Ramadan on maternal nutrition and
composition of breast milk. Pediatr Int. 2006;48(3):278-83
Adolescent
Adult
Breast feeding
Fasting/physiology*
Female
Humans
Infant
Islam*
Maternal nutritional physiological
phenomena/physiology*
Milk, Human/metabolism*
Nutritional status*
Turkey
Subject tree for infants in
Medline®
• Persons Category
– Persons
• Age Group
– Infant
» Infant, Newborn
» Infant, Low birth weight
• Infant, Small for gestational
age
• Infant, Very low birth weight
• Infant, Extremely low
birth weight
» Infant, Postmature
» Infant, Premature
Exploding your subject
• Persons Category
– Persons
• Age Group
– Infant
» Infant, Newborn
» Infant, Low birth weight
• Infant, Small for gestational
age
• Infant, Very low birth weight
• Infant, Extremely low
birth weight
» Infant, Postmature
» Infant, Premature
Focusing your subject
•
•
•
•
•
•
•
•
•
•
•
•
Adolescent
Adult
Breast feeding
Fasting/physiology*
Female
Humans
Infant
Islam*
Maternal nutritional physiological phenomena/physiology*
Milk, Human/metabolism*
Nutritional status*
Turkey
Subheadings
•
•
•
•
•
•
•
•
•
•
•
•
Adolescent
Adult
Breast feeding
Fasting/physiology*
Female
Humans
Infant
Islam*
Maternal nutritional physiological phenomena/physiology*
Milk, Human/metabolism*
Nutritional status*
Turkey
pg. 11
1.
2.
3.
4.
5.
6
• Scoping your search topic
• Choosing the resources to search
• Choosing your search terms
• Compiling your search strategy and running your search
• Finding the full text
• Managing your information
pg. 7
Using Boolean operators - OR
South America
Chile
Brazil
Argentina
South America OR
Brazil OR Argentina
OR Chile
pg. 11
Using Boolean operators - AND
dengue
dengue AND weather AND
South America
South
America
weather
Truncation
• Truncation finds alternative endings to words.
• Enter the beginning of the word, then end with
the truncation symbol (usually *)
Example
You could type in ‘breastfeeding’, ‘breastfed’, ‘breastfeed’
OR
You could type in ‘breastfe*’
Wildcards
Optional
• Character does
NOT have to be
present
• Useful for US/UK
spelling
• eg tumo?r
Compulsory
• Character DOES
have to be present
but can be any letter
• Useful for US/UK
spelling
• eg organi#e
Proximity searching
• Look for words in the same sentence
or within n words of each other
• Useful when the vocabulary used to
describe your subject is variable
Example
You could type in breast milk, breast feeding, breast fed,
OR
You could type in breast adj3 (milk or feed* or fed)
Impact of increased complexity on
comprehensiveness of results
1
alcohol consumption
22,766
2
alcohol consum*
23,355
3
alcohol consum* OR alcohol intake OR beer consum* or beer
intake or binge drink*
30,950
4
((alcohol* OR beer OR wine OR lager OR spirit* OR drink)
ADJ3 (consum* OR unit* OR purchas* OR use* OR intake OR
binge)) OR drink* rate* OR drunk*
57,702
5
((alcohol* OR beer OR wine OR lager OR spirit* OR drink)
ADJ3 (consum* OR unit* OR purchas* OR use* OR intake OR
binge)) OR drink* rate* OR drunk* OR alcohol drinking/
80,221
Numbers correspond to number of results retrieved
from Ovid MEDLINE® 1946 to May week 3 2012.
Putting it all together
1. Ramadan or fasting
2. Fasting/
3. breast adj3 (milk or feed* or fed) or breastfe* or
lactation
4. Breast feeding/
5. nutrit* or nutrient* or diet*
6. exp Nutritional Sciences/
7. exp Diet/
8. 1 or 2
9. 3 or 4
10.5 or 6 or 7
11.8 and 9 and 10
Exercise 5
Page 14
pg. 13
1.
2.
3.
4.
5.
6
• Scoping your search topic
• Choosing the resources to search
• Choosing your search terms
• Compiling your search strategy and running your search
• Finding the full text
• Managing your information
Routes to access
IP address
Resource specific
password
Institution specific
password
Linked to the
computer you are
using
Can be used from
any computer
Can be used from
any computer
Must be using
designated
computer for this
to work
Requires users to
remember
multiple
passwords
Users only need
to remember one
password
The School uses IP addresses and the institutional password
system called Shibboleth. We do NOT use Athens
pg. 15
1.
2.
3.
4.
5.
6
• Scoping your search topic
• Choosing the resources to search
• Choosing your search terms
• Compiling your search strategy and running your search
• Finding the full text
• Managing your information
Reference management software
What
does it
do?
Database of YOUR references
Where
can I
get it?
EndNote installed on all School computers. Can be purchased at educational discount
Can I
get
help?
IT Training run classes in EndNote
Automatically import citations from databases and e-journals
Import and manage PDF files
Import citations into Word documents and format bibliographies
Mendeley is free online
Zotero is free online
IT Training have written short guides on Mendeley and Zotero
Before next week...
Jane Falconer
jane.falconer@lshtm.ac.uk
Improving health worldwide
www.lshtm.ac.uk