Communications technologies are far from equal when it comes to conveying the truth. The first study to compare honesty across a range of communications media has found that people are twice as likely to tell lies in phone conversations as they are in emails. The fact that emails are automatically recorded--and can come back to haunt(困扰) you--appears to be the key to the finding.
Jeff Hancock of Cornell University in Ithaca, New York, asked 30 students to keep a communications diary for a week. In it they noted the number of conversations or email exchanges they had lasting more than 10 minutes, and confessed to how many lies they told. Hancock then worked out the number of lies per conversation for each medium. He found that lies made up 14 per cent of emails, 21 per cent of instant messages, 27 per cent of face－ to-face interactions and an astonishing 37 per cent of phone calls.
His results, to be presented at the conference on human-computer interaction in Vie
A. honesty should be encouraged in interpersonal communications
B. more employers will use emails to communicate with their employees
C. suitable media should be chosen for different communication purposes
D. email is now the dominant medium of communication within a company
Communications technologies are far from equal when it comes to conveying the truth. The first study to compare honesty across a range of communications media has found that people are twice as likely to tell lies in phone conversations as they are in emails. The fact that emails are automatically recorded--and can come back to haunt(困扰) you--appears to be the key to the finding.
Jeff Hancock of Cornell University in Ithaca, New York, asked 30 students to keep a communications diary for a week. In it they noted the number of conversations or email exchanges they had lasting more than 10 minutes, and confessed to how many lies they told. Hancock then worked out the number of lies per conversation for each medium. He found that lies made up 14 per cent of emails, 21 per cent of instant messages, 27 per cent of face－ to-face interactions and an astonishing 37 per cent of phone calls.
His results, to be presented at the conference on human-computer interaction in Vie
A. the consequences of lying in various communications media
B. the success of communications technologies in conveying ideas
C. people's preferences in selecting communications technologies
D. people's honesty levels across a range of communications media
设有关系肛(A，B，C) ，与SQL语句select distinct A,C from R where B=5等价的关系代数表达式是（）。
Ⅰ．πA,C(σB=5(R))
Ⅱ．σB=5(πA,C(R))
设有关系R=(A,B,C)，与SQL语句select distinct A,C from R where B=5 等价的关系代数 表达式是（）。
I. πA,C(σB=5(R))
II. σB=5(πA,C (R))
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