Page 196 - Ana Kozina and Nora Wiium, eds. ▪︎ Positive Youth Development in Contexts. Ljubljana: Educational Research Institute, 2021. Digital Library, Dissertationes (Scientific Monographs), 42.
P. 196
positive youth development in contexts
effects were reported for interventions with sessions lasting less than 20
minutes, while sessions of a moderate length produced the largest effects.
The relationship between intervention effectiveness and session length may
be described as an inverted-U curve whereby interventions of a moder-
ate duration (30–60 min) are the most effective. Shorter sessions may im-
pose serious time constraints on the administrators, forcing them to rush
through the whole intervention procedure. Not enough time is then giv-
en for adequate instruction, while students may not have sufficient time to
properly finish a given task. Longer sessions might not contribute to inter-
vention effectiveness due to the fatigue of participants and intervention ad-
ministrators, causing them to lack in concentration and motivation.
However, the results cannot be generalised as one study with three
1-hour-long sessions (Vezzali et al., 2015a) recorded many large effects,
which outweighed the effect sizes of the other studies in the analysis. If we
were to exclude this study, three-session interventions would report pre-
dominantly small effects and 30- to 60-minute interventions would most-
ly report negligible positive effects. Still, a linear trend can be observed in
terms of the number of sessions since the effectiveness of interventions in-
creases with their number.
Interventions seem to be most effective when they have multiple ses-
sions and are moderate in length. This is in line with the findings of Ülger
et al. (2018) that longer interventions with multiple sessions effects are sta-
tistically significant, while short one-off interventions effects are statisti-
cally non-significant. Yet, only one of the latter was included in our review,
which makes it impossible to generalise the findings. Negligible effects
might also be due to the poorer methodological quality of a study (see Table
1). Nevertheless, our results indicate that frequent and long-term direct or
indirect exposure to members of an ethnic outgroup can more effective-
ly reduce prejudice since the likelihood of positive interactions and expe-
riences with members of the outgroup has increased (Brown & Hewstone,
2005).
Outcomes of contact-based interventions
Direct contact interventions had moderate-to-large effects on behaviour-
al outcomes (i.e. propensity to discriminate, intention to help an outgroup
member), large effects on cognitive outcomes (i.e. negative stereotypes) and
a moderate effect on affective outcomes (i.e. negative emotions towards the
outgroup) (see Table 1).
196
effects were reported for interventions with sessions lasting less than 20
minutes, while sessions of a moderate length produced the largest effects.
The relationship between intervention effectiveness and session length may
be described as an inverted-U curve whereby interventions of a moder-
ate duration (30–60 min) are the most effective. Shorter sessions may im-
pose serious time constraints on the administrators, forcing them to rush
through the whole intervention procedure. Not enough time is then giv-
en for adequate instruction, while students may not have sufficient time to
properly finish a given task. Longer sessions might not contribute to inter-
vention effectiveness due to the fatigue of participants and intervention ad-
ministrators, causing them to lack in concentration and motivation.
However, the results cannot be generalised as one study with three
1-hour-long sessions (Vezzali et al., 2015a) recorded many large effects,
which outweighed the effect sizes of the other studies in the analysis. If we
were to exclude this study, three-session interventions would report pre-
dominantly small effects and 30- to 60-minute interventions would most-
ly report negligible positive effects. Still, a linear trend can be observed in
terms of the number of sessions since the effectiveness of interventions in-
creases with their number.
Interventions seem to be most effective when they have multiple ses-
sions and are moderate in length. This is in line with the findings of Ülger
et al. (2018) that longer interventions with multiple sessions effects are sta-
tistically significant, while short one-off interventions effects are statisti-
cally non-significant. Yet, only one of the latter was included in our review,
which makes it impossible to generalise the findings. Negligible effects
might also be due to the poorer methodological quality of a study (see Table
1). Nevertheless, our results indicate that frequent and long-term direct or
indirect exposure to members of an ethnic outgroup can more effective-
ly reduce prejudice since the likelihood of positive interactions and expe-
riences with members of the outgroup has increased (Brown & Hewstone,
2005).
Outcomes of contact-based interventions
Direct contact interventions had moderate-to-large effects on behaviour-
al outcomes (i.e. propensity to discriminate, intention to help an outgroup
member), large effects on cognitive outcomes (i.e. negative stereotypes) and
a moderate effect on affective outcomes (i.e. negative emotions towards the
outgroup) (see Table 1).
196
