Not all participants are the same. researchers use to reduce the possibility that preexisting differences between groups are responsible for observed differences after experimental manipulation.

Identify the example of when situation and time are key to assessing risk of harm in a research study: a study on the efficacy of a behavioral intervention for smoking cessation involves both adults and teenagersasking women if they have had an abortionresearch on the prevalence of hiv-infected individuals in communitiesa survey about sexually transmitted diseases

In a small, closed economy, national income (gdp) is $350 million for the current year. individuals have spent $100 million on the consumption of goods and services. they have paid a total of $60 million in taxes and the government has spent $75 million on goods and services this year. use this information and the national income identity to answer the questions. how much does the economy spend on investment?

Should the city pass a ban on skateboarders on all public property, or are the citizens who oppose the ban right when they argue that there are benefits to having the skateboarders in public parks? plan and write a response in which you state your position and persuade readers to agree with you. support your position with reasons and examples drawn from the proposed amendment to ban skateboarding and from information in the letters to the editor, as well as from your own experience.