Types of Research and Prenatal Diagnostic Tests Flashcards
Lifespan Development, Module 2 Notes, Pages 1-7
Longitudinal study design
and example
Follows individuals over long period of time with multiple assessment points
Example: children in longitudinal study are asked about social groups at age 10, 13, 15
Studies in human development are more likely to use _________ study design than other fields
human development studies are more likely to use longitudinal study design than other fields
Advantages of longitudinal study design
- enables researchers to tease out if phenomenon is due to developmental changes (becoming older/mature) or inherent to individual
- Explores what qualities change over time and what qualities remain stable
Disadvantages of longitudinal study design
- the longer the study, the more time and resources needed
- difficult for people to commit multiple years (or decades) of their lives to single study
Cross-sectional study
And example
study that compares different age groups at the same time
Example: study that includes 3 groups of children and teens, divided by age, who are asked about social groups
Advantages of cross-sectional studies
- more time efficient than longitudinal study
- participants less likely to drop out of study
Disadvantages of cross-sectional studies
- since children aren’t followed over time, it doesn’t observe how children develop over time; simply examines how they are currently
Can longitudinal and cross-sectional designs be combined?
Yes, longitudinal and cross-sectional designs can be combined
(2 types of approaches must also be chosen in addition to research design method
Example: researcher might choose longitudinal experimental design and cross-sectional survey design)
Types of research designs
Naturalistic observation Case study Survey Correlational study Experiment
Why is it important to discuss research design?
and example
helps you understand how knowledge was obtained so you can better interpret the information
(example: Understanding Freud’s study population only involved his neurotic clients helps us realize that info may not be applicable to larger, healthy population)
Naturalistic Observation
and example
research design that involves observing subject outside of research setting & in a more natural location that is subject’s everyday environments (home, school, public setting)
Example: Piaget observed children at play at home
Advantages of Naturalistic Observation
Can observe natural behaviors
Disadvantages of Naturalistic Observation
- Can only access behavior you observe (not getting in person’s head or learning much outside of that context)
- People may notice they’re being watched and subtly change behavior
Case study
research design involving a very detailed examination of an individual through direct observation & interviewing participant in great detail (& usually also people close to individual)
When are using case studies most helpful?
For unique and unusual situations (such as studying a rare disorder)
Advantages of case study
detailed information
Disadvantages of case study
subjectivity & generalizability (results may not be applicable to general population)
Survey/Interview
& how can it be administered?
research design that asks questions about attitudes, opinions & frequencies of certain behaviors
Can be administered in person or anonymously via internet/mail
Formats of surveys/interviews
Questionnaire
Self-report
In-person surveys use an interview format
Advantages of Survey
- time & cost efficient
- low level of involvement (could print survey off of internet)
- wide reach of sample (larger sample= greater chance of its generalizability)
Disadvantages of Survey
explain
self-report measures
Anytime asking subject to report on own behavior:
- hope for truthful response
- hope response is accurate (their perception/memory may be skewed)
- do they have cognitive processes to think about own behavior & respond in accurate way
Why are self-report measures a disadvantage?
only takes a handful of inaccurate responders or skipping over answers to skew results or affect generalizability because may or may not accurately reflect population being studied
Correlational research
& example
Research design that explains how 2 variables relate to each other.
Statistics are used to indicate strength/degree & direction of relationship between variables.
Example: number of friendships increase with age?
How is information gathered for correlational research?
via survey or interview
What does the ‘degree’ tell you in correlational research?
tells you how strong correlation is
What does the ‘direction’ tell you in correlational research?
indicates whether both variables increase together (positive relationship), or if one variable increases when the other decreases (negative/inverse relationship)
Give example of a negative association in correlational research
as one gets older, they throw fewer temper tantrums
Advantages of correlational research
answers key questions (about how things relate)
Disadvantages of correlational research
& elaborate
correlation does not equal causation
Elaboration: news or media source can pick up finding reported in psychology journal and mangle message so correlation gets mistaken for causation
- happens a lot in food & nutrition studies
Experiments
Research design in which researcher tightly controls the setting, participants & variables in study and manipulates a factor believed to have some influence
Key aspects of experiments
manipulation & control
What is manipulated variable in drug treatment study?
treatment is the manipulated variable
How is manipulation involved in research setting?
Typically have more than one participant group (group receiving psychotherapy, group receiving treatment & control group)
Manipulation observed by setting up several groups & randomly assigning participants to one of the groups
Why do experiments need to be in controlled settings?
Don’t know how other factors (age, race, gender) will influence how participant handles certain drugs/treatment being studied
- Need something to compare it to (control group vs experimental group)
What research design type is the only one to adequately discern whether manipulated variable caused a change? Explain.
Experimental studies
Other studies don’t allow for researcher to deem causation since random group assignments and manipulation of experimental variable are typically absent from other study designs
Advantages of experimental research design
addresses causation
observe cause & effect unfolding in front of you through use of manipulation & control
Disadvantages of experimental research design
Hawthorne Effect
What is Hawthorne Effect?
idea that people may behave differently in a study due to lab environment or wanting to please researcher by giving ‘right’ answers
What research designs are opposite each other?
Experiment & naturalistic observation
List prenatal diagnostic tests
- Ultrasound
- Amniocentesis
- Chorionic Villus Sampling
What issues are there regarding prenatal diagnostic tests?
- Balance between obtaining information & protecting the mother and child
- May play controversial role in abortion decisions
What do prenatal diagnostic tests do?
Discern baby is developing normally
Ultrasound (sonogram)
Imaging technique that directs high frequency sound waves into mother’s abdomen and uses the soundwave’s echo to create image of developing baby.
Offers reassurance baby is growing & developing normally
What can ultrasounds show?
Baby’s position, gender, gestational age, some brain defects
Ultrasound- invasive/safe?
What’s the general rule regarding number of ultrasounds?
What’s the potential risk?
Non-invasive, considered safe
General rule: fewer than 5 during pregnancy
(5+ associated with increased risk of low birth weight)
Which is why should only be done for valid medical reasons- not to determine baby’s sex
First ultrasound done during first trimester to:
list 5
Evaluate presence, size & location of pregnancy
Determine number of fetuses
Estimate gestational age (how long you’ve been pregnant)
Genetic screening
Screening for mother’s uterine/cervix abnormalities
When is the second ultrasound typically done?
During second trimester when anatomic details are visible to evaluate fetal anatomy
Usually between 18-20 weeks
Why might they recommend follow-up ultrasounds/additional imaging tests (such as MRI)?
If problem is detected from first two ultrasounds
List 2 main types of ultrasound
Transvaginal
Transabdominal
Transvaginal
Transducer (wand-like device) placed in vagina to send out sound waves & gather reflections
Used most often during early pregnancy
Might be done if transabdominal didn’t provide enough info
Transabdominal
Performed by moving transducer over abdomen
Various types of transabdominal ultrasounds done when anomaly suspected based on parent’s history or prenatal exam results
Fetal ultrasound might be used to
list 9
Confirm pregnancy & location Determine gestational age Confirm number of babies Evaluate baby's growth Study placenta & amniotic fluid levels Identify birth defects Investigate complications Perform prenatal tests Determine fetal position before delivery
Amniocentesis
Involves removing sample of amniotic fluid through syringe between weeks 15-20
Tests fluid for chromosomal & genetic abnormalities and neural tube defects (such as spina bifida)
Purpose of amniotic fluid
list 4
Protects fetus from injury
Protects against infection
Allows baby to move & develop properly
Helps control fetus temperature
Amniocentesis- invasive/safe?
What’s the potential risk?
More invasive than ultrasound
Risk of miscarriage (1 in 300 women miscarry after amniocentesis)
When is amniocentesis done?
Why is it done?
Late pregnancy (2nd or 3rd trimester) - To check fetal well-being & diagnose fetal health problems
{Done to check fetal lung maturity if baby is expected early}
How is amniotic fluid tested on twins, triplets, etc.
fluid samples taken from each amniotic sac to study each baby
Factors that interfere with amniocentesis
- Pregnancy earlier than 14 weeks
- Position of baby, placenta, amount of fluid, mother’s anatomy
Twins, triplets, etc. because of need to test each amniotic sac
Chorionic Villus Sampling (CVS)
Involves inserting tube & removing tissue from end of 1 or more chorionic villi
Chorionic Villi
Hair-like projections on placenta (membrane) of developing child
Placenta
Membrane of developing child
When is chorionic villus sampling performed?
Between 10 & 12 weeks (in first trimester)
Why is chorionic villus sampling performed?
Used to detect genetic abnormalities
Chorionic Villus Sampling- invasive/safe?
What’s the potential risk?
Considered invasive
Higher risk of miscarriage than with amniocentesis
Leaking of amniotic fluid (water breaking)
Preterm labor
Risk of causing limb deformity
What does chorionic villus sampling not provide info on?
Neural tube defects (such as spina bifida)
How to women getting CVS screen for neural tube defects?
They get follow-up blood test at 16-18 weeks
2 types of chorionic villus sampling
Transcervical & Transabdominal
Transcervical CVS
Catheter inserted through cervix into placenta to obtain tissue sample
Transabdominal CVS
Needle inserted through abdomen & uterus into placenta to obtain sample
How is CVS tested on twins, triplets, etc.
Need samples from each placenta to study each baby
