Indeed, camera and video are necessary for the evidence of a research. Children as a participant, consent, permission from parents or guardians are needed, in order to protect children privacy and rights. However, each observation method has each strength and concerns. Controlled observation is more representative, researchers can collect large sample of data, it is a challenge for the researcher to have numerous consents from children, however, this observation is the lack of validity, participants can act differently because of knowing they are being watched. Natural observation is able to observe the flow of behavior in the research, conversely, it is less reliable, sometime this observation will lack consents, difficult to ask questions and take notes because researcher hiding the fact of observing the participant. Participant observation is easily lead researcher to lose objectivity, thus, fail the findings researchers are expecting. However, Piaget 's conservation task has demonstrated how different stage of young children succeeds and fail to provide an explanation of the judgment, therefore, language development is one of the challenges while undertaking an experiment with young children …show more content…
Research ethics is to protect and respect participant throughout an empirical work, finical, professional pressures and question addressed to children need to be ethical (ncb,2011), however, this is a challenge for researchers to decide what questions should be asked by addressing no stress and force but it can encourage the participant to continue with the experiment. Reward should be an approach for participant 's benefits, nevertheless, researchers need to consider that should children be rewarded for taking part in research. Moreover, children at the same age have a different understanding of the world depending how children educated and developed (Bronfenbrenner, 1996). Piaget 's cognitive development research have shown there are different stages that children went through, however, age 12 young children already have cognitive of rules, in addition, demand characteristic makes participants note what is the experiment expected and how participants expected to behave, but it could also affect the performance of guessing the answer wrong. Moreover, Margaret Donaldson mentioned Piaget and Hughes ' research experiment, have emphasized the importance of experiment named, the position set and explained to the participants, because this two experiment have the same aim to find out when children largely lost egocentric thinking, however, the complex of the experiment fully affects the