This research
tapped into the challenge of long-term engagement
in children with social robots, which tend to wear off
even within one session.
In order for social robots in education to be successful
long-term interaction are essential
which means that children need to remain motivated
to engage in learning tasks provided by the robot
over multiple sessions.
Since motivation is a prerequisite for task engagement
it is necessary to motivate children when interacting
with a social robot.
In our research we incorporated the
Self-Determination Theory by Deci and Ryan
into the social robot NAO.
This influential theory on motivation from psychology
states, that intrinsic motivation thrives mainly on
three intertwined psychological needs.
These are, autonomy, competence, and relatedness.
The latter plays a substantial role in maintaining
intrinsic motivation.
We aimed to investigated whether a social robot,
supporting these three basic human needs,
could affect children's task engagement and
learning gain in second language learning
We carried out an experiment with fourty nine
Dutch native speaking children of
of five and six years old.
The children played thirty rounds of
"I spy with my little eye", using NAO as a tutor.
We adopted the baseline condition of De Wit et al.
as our control condition,
and we compared this with
two conditions applying motivational strategies.
One condition only
satisfied the need for autonomy and competence,
the other condition also satisfied
the need for relatedness.
The need for autonomy was implemented by
granting choice to the child.
The need for competence was implemented by
providing positive feedback sentences
and by showing performance contingent awards.
Hippo.
That one was difficult.
Hippo.
Is the English word for hippo.
Just click on the
hippo.
Wow, that is great.
The need for relatedness was implemented by
placing the robot close to the child
at a 45-degree angle.
The robot also asked the child, what his or her
favourite colour was, after which the background colour
of the tablet changed into that colour.
You may pick the colour of the tablet today.
What is your favourite colour?
Green.
How nice. Green is also my favorite colour.
The robot also used the child's name in the feedback
sentences, and the robot suggested a fist bump.
We hypothesized that,
children's task engagement is stronger when all three
needs are satisfied
and that they remain engaged over time
compared to the other two conditions.
We also hypothesized that children will learn more
target words and will remember those
words longer compared to the other two conditions.
Finally, we hypothesized that task engagement
positively correlates with learning gain.
The experiment consisted of six phases.
A group introduction, which consisted of a background
story to frame NAO as a peer named 'Robin'.
A Dutch pretest and an English pretest
to test the children's prior knowledge
of the six target words;
bird, monkey, horse, ladybug, hippo, and chicken
These words were identical as in the Wit et al.
The concept binding,
to provide the children with a correct match between
the L2 target word and the corresponding image.
The experimental phase. This phase consisted of
two test rounds. One in Ducht, and one in English,
followed by the actual experiment of thirty rounds of
'I spy with my little eye'. The robot said in Dutch:
"I spy with my little eye a...."
followed by target words in English, after which
the child had to select the picture on the tablet.
And an immediate post-test and a delayed post-test
after one week
to test learning gain and long-term retention
of the L2 target words.
We measured task engagement using a coding-scheme
on a 5-point scale with 0.5 intervals.
We coded 2-minute videos of the 4th and 24th round
using two raters.
They were found to have a moderate to good
inter-rater reliability.
We measured learning gain by subtracting
the results from the pretest from the post-tests.
We carried out four one-way ANOVAs with
planned contrast, to examine the motivational
support interventions on child's task engagement
and learning gain.
Overall, the mean task engagement of children was
higher in the ACR-condition, compared to
AC-condition and the Control condition.
The one-way ANOVA revealed a significant effect
of condition on the mean task engagement
with a p-value of .022.
And planned contrast showed that children in the
ACR-condition were more engaged towards the robot
compared to children in the AC-condition.
There was no significant difference
when comparing the AC-condition and
the ACR-condition with the Control-condition.
The figure also showed that the drop in children's
engagement was the smallest in the ACR-condition,
compared to the other two conditions.
A second one-way ANOVA revealed a significant
effect of condition on the drop in engagement
with a p-value of .017.
Planned contrast revealed that the ACR-condition and
the AC-condition
task engagement dropped significantly less than
in the Control condition.
There was however, no significant difference
between the ACR-condition and the AC-condition.
So, the data did support hypothesis 1b and 2a,
it did however not support hypothesis 1a and 2b.
Children's immediate learning gain of L2 words
were the highest in the ACR-condition,
compared to the AC-condition and
the Control condition.
However, these differences were not significant.
Similarly, children's delayed learning gain
was the highest in the ACR-condition
compared to the AC-condition,
and the Control condition,
but again these differences were not significant.
So, the data dit not support hypotheses 3 and 4.
Finally, we analyzed the correlation between the mean
task engagement and the immediate learning gain
and between mean task engagement and
the delayed learning gain,
but there were no significant correlations.
Although, we did found a significant correlation
in the AC-condition.
So, the data did not support hypothesis 5.
So, our study is a first attempt
to implement an intervention to support the
psychological needs for autonomy, competence, and
relatedness into a social robot.
The most important finding is that motivational
strategies which satisfy all psychological needs
seem to keep children engaged over a longer
period of time.
Our results show, that it is possible to overcome
the wearing off of motivation over time,
which is essential within the educational setting.
Since we implemented multiple motivational
strategies,
further research is needed to disentangle
the contributing to task engagement of each
motivational strategy.
Contrary to our expectations, our study did not find
a significant difference in immediate
nor delayed learning gain.
One possible reason could be the large variation
between children.
We also expect that with more power,
that is a sample size of 250 children,
it would have been likely that the ACR-condition
would have revealed a significant effect.
We encourage more experimental well-powered
research to further investigate the effect of
motivational strategies on learning gain.
To conclude,
this study suggests that it is beneficial to implement
motivational strategies in a robot tutor,
supporting the psychological needs for autonomy,
competence and relatedness.
Since, we found promising results on children's
task engagement and keeping children engaged
over time.
In particularly, the need for relatedness
seems to positively affect children's motivation
towards an L2 word learning task.