Strengths and Weaknesses of Research Designs Description Strengths Weaknesses Correlational Design Researcher sees if changes in one variable are accompanied by systematic changes in another variable. Useful when conditions do not permit the manipulation of variables. Cannot determine cause-and-effect relationships. Experimental Design Researcher manipulates one of more independent variables to observe the effects on the dependent variable(s). Can isolate cause-and-effect relationships. May not yield information about real-life behaviors. Field Experiment Experiment conducted in real-life, naturalistic settings. Can isolate cause-and-effect relationships; behaviors are observed in natural settings. Less control over treatment conditions. Quasi-experiment Assignment of participants to groups is determined by their natural experiences Takes advantage of natural separation of children into groups. Factors other than independent variables may be causing results. Single-Case Design In-depth observation of one or a few children over a period of time. Do not require large pool of participants. Ability to generalize to the larger population may be limited.

ERIKSON’S PSYCHOSOCIAL STAGES Trust vs. Mistrust Autonomy vs. Shame and Doubt Initiative vs. Guilt Industry vs. Inferiority Identity vs. Role Confusion Intimacy v. Isolation Generativity vs. Stagnation Ego Integrity vs. Despair Birth – 1 year 1 - 3 years 3 - 6 years 6 - 12 years (Latency Period) 12 - 19 years (Adolescence) 19 – 25 years (Early Adulthood) 25 – 50 years (Adulthood) 50 years and older

PIAGET’S COGNITIVE STAGES Sensorimotor Preoperational Concrete Operational Formal Operational Birth - 2 years 2 – 7 years 7 – 11 years 11 years - adulthood Child develops schemes primarily through sense and motor activities Child can think symbolically; holds egocentric view of the world Child becomes able to manipulate logical relationships among concepts but only by generalizing from concrete experiences Child is able to deal with abstractions, form hypotheses, solve problems systematically

The human body contains 100 trillion cells. There is a nucleus inside each human cell (except red blood cells). Each nucleus contains 46 chromosomes, arranged in 23 pairs. One chromosome of every pair is from each parent. The chromosomes are filled with tightly coiled strands of DNA. Genes are segments of DNA that contain instructions to make proteins— the building blocks of life.

The Process of Mitosis Each daughter cell now has a pair of chromosomes that is identical to the original pair Cell nucleus with a pair of chromosomes Chromosomes split and replicate to produce two identical pairs The pairs separate, and the cell divides

Implantation of the Embryo The Germinal Stage of Prenatal Development Zygote Implantation of the Embryo Fallopian tube Fallopian tube Ovary Ovary Uterus Embryo joined to uterine wall Cervix Vagina Blastocyst

Embryonic period (in weeks) Fetal period (in weeks) Full term 3 4 5 6 7 8 12 16 20 36 38 Brain Central nervous Eye system Ear Palate Ear Heart Eye Arm Heart Leg Teeth External genitalia Central nervous system Heart Arms Eyes Legs Teeth Palate External genitalia Ear Period when major Period when minor defect or abnormality occurs abnormality occurs

Spine Bladder Pubic bone Potential width of Cervix birth canal Vagina Coccyx Rectum The baby in the uterus before labor Water about to break (The baby's head now rests inside the cervix) Transition: The baby in the birth canal STAGE 1 The baby about to be born The head rotates sideways after it emerges The delivery of the placenta STAGE 2 STAGE 3

Less than 100 beats per minute InRev1 The Apgar Scale Score Characteristic 1 2 Heart rate Efforts to breathe Muscle tone Skin color Reflex irritability Absent Flaccid,limp Body pale or blue No response Less than 100 beats per minute Slow, irregular Weak, inactive Body pink, extremities blue Frown, grimace More that 100 beats per minute Good; baby is crying Strong, active motion Body and extremities pink Vigorous crying, coughing, sneezing Source: Apgar (1953)

Body Proportions, Fetal Period Through Adulthood 2 months (fetal) 5 months (fetal) Newborn 2 years 6 years 12 years 25 years

The Episode of the Strange Situation Number of Episode Persons Present Duration Brief Description of Action 1 2 3 4 5 6 7 8 Mother, baby, and observer Mother and baby Stranger, mother, and baby Stranger and baby Baby alone 30 seconds 3 minutes 3 minutes or lessa 3 minutes or moreb Observer introduces mother and baby to experimental room, then leaves. Mother is non-participant while baby explores; if necessary, play is stimulated after 2 minutes. Stranger enters. Minute 1: stranger silent. Minute 2: stranger converses with mother. Minute 3: stranger approaches baby. After 3 minutes mother leaves unobtrusively. First separation episode. Stranger's behavior is geared to that of baby. First reunion episode. Mother greets and comforts baby then tries to settle him again in play. Mother then leaves, saying bye-bye. Second separation episode. Continuation of second separation. Stranger enters and gears her behavior to that of baby. Second reunion episode. Mother enters, greets baby, then picks him up. Meanwhile stranger leaves unobtrusively. aEpisode is curtailed if the baby is unduly distressed. bEpisode is prolonged if more time is required for the baby to become involved in play. Source: Campos et al., 1983.