U.S. Department of Justice
Office of Justice Programs
Bureau of Justice Statistics

Intimate Partner Violence and
Age of Victim, 1993-99


October 2001, NCJ 187635

revised 11/28/01 th


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This file is text only without graphics and many of the
tables.  A Zip archive of the tables in this report in
spreadsheet format (.wk1) and the full report including
tables and graphics in .pdf format are available from:
http://www.ojp.usdoj.gov/bjs/abstract/ipvva.htm

This report is one in a series.  More recent editions may 
be available. To view a list of all in the series go to 
http://www.ojp.usdoj.gov/bjs/pubalp1.htm#Intimate Partner
Violence and Age of Victim
---------------------------------------------------------

By Callie Marie Rennison, Ph.D.
BJS Statistician

---------------------------------------------------------
Highlights

Women accounted for 85% of the victims
from among the more than 790,000 victims 
of intimate violence in 1999; women age 
16 to 24 were the most vulnerable to 
intimate violence

*  Intimate partner violence rates differ
greatly based on the age of the victim. 
While the overall per capita rate of
intimate partner violence against women 
was 5.8 victimizations per 1,000 in 1999, 
among females age 16-24, it was 15.6 per 
1,000.  

*  Between 1993 and 1999 the overall rate 
of intimate partner violence against all 
females decreased 41% from 10 to 6 
victimizations per 1,000 females age
12 or older.  Rates of intimate partner
violence fell for females age 20-24,
25-34, and 35-49.  

*  Black and white females experienced
intimate partner violence at similar 
rates for every age group examined except
age 20-24. For this age, there were 29
intimate partner victimizations per 1,000
black women and 20 per 1,000 white
women. 

*  Women separated from their husbands 
were victimized by an intimate at rates 
higher than married, divorced, widowed, 
or never married women. 
 
*  Intimate partners murdered 1,218
women during 1999.  From 1993 to 1999 
intimates killed 32% of all female
murder victims age 20-24.

*  Women age 35-49 were the most
vulnerable to intimate murder.
----------------------------------------------------------

Estimates from the National Crime
Victimization Survey (NCVS) indicate
that in 1999 persons age 12 or older
experienced about 791,210 violent
crimes by a current or former spouse,
boyfriend, or girlfriend.  Intimate 
partner violence is primarily a crime
against women:  During 1999 females
experienced 671,110 (85%) such violent
victimizations; males, 120,100 (15%).

Younger women generally had higher
rates of intimate partner violence than
older women.***Footnote 1: In general,
information about intimate partner victimi-
zation of males is not provided because
the small number of cases in each age 
category was not sufficient for reliable 
estimates.***  The 1999 per capita rate 
of intimate partner violence against
women was 6 victimizations per 1,000;
per 1,000 females age 16-24, it was 16
victimizations, and per 1,000 females
age 25-34,9 victimizations.

Overall, older women experienced intimate 
partner violence at rates that were about 
equal among different ethnic or racial 
groups.  Only among women age 20-24 did 
blacks experience more intimate violence 
than whites. 

Between 1993 and 1999 the rates of
intimate partner violence for women age
20-49 declined.  The rates for women of
other ages did not change significantly. 

Data

Findings regarding violent crime are
drawn from National Criminal Victimi-
zation Survey (NCVS) data collected by 
the Bureau of Justice Statistics (BJS).  
Homicide data were collected by the FBI, 
under the Supplementary Homicide Reports 
(SHR) of the Uniform Crime Reporting 
Program (UCR).

----------------------------------
Victims age 65 or older Annual rates 
for victims of nonfatal intimate partner 
violence age 65 or older are displayed 
in appendix. The rates are combined 
with those of the 50-64 age group 
elsewhere because the number of sample 
cases of women age 65 or older was too 
small to provide reliable estimates.  
Where possible, discussions of homicide 
display data for victims age 65 or older.
-------------------------------------

-------------------------------------
The National Crime Victimization
Survey 

The NCVS is the Nation's primary
source of information on the frequency,
characteristics, and consequences of
criminal victimization.  One of the 
largest continuous household surveys
conducted by the Federal Government,
the NCVS collects information about
crimes both reported and not reported 
to police.  The survey provides the 
largest national forum for victims to 
describe the impact of crime and the 
characteristics of violent offenders.

This report is one in a series. Previ-
ous reports include the following: 
Intimate Partner Violence, NCJ 178247 
and Violence by Intimates, NCJ 167237.
Findings from the  NCVS are also on 
the BJS website: www.ojp.usdoj.gov/bjs/
-------------------------------------

Definitions

For this report, intimate relationships 
are defined as those involving current 
or former spouses, boyfriends, or
girlfriends.  Offenders may be of the
same gender as the victim.  

Violent acts examined include murder,
rape, sexual assault, robbery, aggra-
vated assault, and simple assault. 

-------------------------------------
Intimate partner homicide of males,
1993-99

In 1999 intimate partner homicides
accounted for 11% of all murders of 
both males and females.  An offender
who was not intimate with the victim
committed the majority of homicides
(55%), and in 34% of murders, the
victim-offender relationship was
unknown. 

Of the 1,642 persons murdered by an
intimate in 1999, 424 -- or 26% -- 
were men.  Male murder victims were
substantially less likely than female
murder victims to have been killed by 
an intimate partner.  In 1999 intimate
partner homicides accounted for 32% 
of the murders of females and about 
4% of the murders of males.

In 1999 intimate partners murdered
males age 35-49 at rates higher than
those of other age categories (0.7 
per 100,000 males).  

Intimates murdered males age 20 to 
34 at rates nearly as high as males
35-49 (0.5 males per 100,000).  In
contrast, intimates murdered males 
ages 12-15, 16-19, or 65 or older at 
the lowest rates -- 0.1 per 100,000 
males at most.  

For victims age 16 or older the 1999
rates of intimate partner homicide
against males were lower than 1993
rates for all age categories examined.
  
By age group homicide rates against
males by an intimate partner decreased
between 29% (males age 20-24) and
58% (males age 25-34), 1993-99.
----------------------------------

Intimate partner violence against
females, 1999

Women were victimized in 85% of the
791,210 intimate partner violent crimes 
in 1999.  Intimate partner violence 
against females most often took the 
form of a simple assault (66%). Fourteen 
percent of female intimate partner 
victims were raped or sexually assaulted.  
Aggravated assaults and robbery each 
accounted for 10% of all intimate partner 
violence against females during 1999. 

Overall, 6 per 1,000 females age 12 or
older were victims of intimate partner
violence during 1999.  This overall rate
masks the variation in per capita rates
for females in different categories of
age.  For example, during 1999 females
age 16-19 and 20-24 were the most
vulnerable to intimate partner violence
(15 and 16 violent victimizations per
1,000, respectively).

Homicide of females by intimates 

As was the case historically, females
were more likely than males to be
murdered by an intimate partner in 1999. 
During the year 74% -- or 1,218 -- of 
the 1,642 persons murdered by an 
intimate partner were female (not shown 
in table).

A substantial percentage of female murder 
victims were slain by an intimate partner.  
In every age category females were more 
likely than males to be murdered by an 
intimate partner.
  
Between 1993 and 1999, an intimate was 
responsible for 45% homicides of women 
age 20-24 and almost 40% of homicides 
of women age 35-49.   

In 1999 women age 35-49 were murdered by 
an intimate partner at rates greater than 
those of all other age groups (2.1 females 
killed by an intimate per 100,000 females.  
Females age 20-24 and 25-34 also had high 
rates of intimate partner homicide. During
1999 an intimate partner killed 1.6
females age 20-24 per 100,000 and 1.7 
females age 25-34 per 100,000.  

In contrast, the youngest and oldest
females (those age 12-15 and 50 or
older) were murdered by an intimate
partner at the lowest rates of all 
females (0.1 and 0.6 per 100,000 
females, respectively). 

The age distribution for homicides differs
from that for nonfatal intimate partner
violence.  Women age 35-49 were the most 
vulnerable to intimate murder, and those 
age 16-19 and 20-24, the most vulnerable 
to nonfatal violence.

From 1993 to 1999 the rates of intimate
partner homicide against females fell for
every age group examined.  The smallest 
percentage decline occurred among females 
age 35-49 -- those with the highest rates 
overall.  Between 1993 and 1999, intimate 
partner homicide for this group fell from 
2.4 to 2.1 murders per 100,000.  

In recent years intimate partner homicide 
rates increased for women in some age 
groups.  For example, between 1997 and 
1999 intimate partner homicide rates 
increased for females age 35-49 and age 
65 or older.***Footnote 1: For more
information on the difficulty associ-
ated with analyzing Supplementary 
Homicide Reports, see Michael D. 
Maltz, Bridging Gaps in Police Crime
Data, BJS report, September 1999, NCJ
176365, pp. 31-30.***

For additional information on intimate
partner homicide trends, visit BJS's 
web site at < www.ojp.usdoj.gov/bjs/
homicide/homtrnd.htm>.

Victim characteristics, 1993-99

The following presents rates of intimate
partner violence by the victims' age,
taking into account one additional
variable, such as race or marital status,
at a time.***Footnote 2: While these
estimates are informative, including
more control variables could modify
the differences in rates between the
age categories.  Because of limits
imposed by sample size, the addition
of multiple control variables simultane-
ously was not possible.***  
                       
Race

The pattern found between rates of
intimate partner violence and victim's
age for all females also was evident
when examining the age profiles of 
black and white females independently.
For both black and white females, age
profiles of intimate partner violence 
rates were similar, peaking at age 
20-24, then decreasing for older age
categories.

In addition to similar overall patterns,
black and white females experienced
intimate partner violence at similar
magnitudes for all age categories 
except one.  Among females age 20-24, 
black women incurred intimate partner 
violence at significantly higher rates 
than white women (29 versus 20 victimi-
zations per 1,000 respectively). 

The age profile pattern between victim's
age and intimate partner violence rates
for females of other races (Asians,
Native Hawaiians, other Pacific Islanders, 
Alaska Natives, and American Indians as 
a whole) was similar to that for black 
and white females.  Intimate partner 
violence estimates for females of other 
races are not discussed in the text 
because of an insufficient number of 
cases.  

Hispanic origin 

The age pattern of intimate partner 
violence among non-Hispanic females
was similar to the pattern for all 
females. The rate of intimate partner 
violence against non-Hispanic women 
peaked at age 20-24 (22 per 1,000), and 
then decreased as the age category
increased.
 
Compared to the rates for non- Hispanic
females, intimate partner violence rates
for Hispanic females peaked at lower
levels and over a wider range of ages. 
For Hispanic females the highest rates
of intimate partner violence occurred
among those age 16-19, 20-24, and
25-34 (12, 13, and 11 victimizations 
per 1,000 Hispanic females, respectively).

Between 1993 and 1999 the rates of
intimate partner violence for non-
Hispanic women age 20-24 and 25-34
were significantly greater than those 
of Hispanic women of comparable ages. 
Non-Hispanic females age 16-19 also
experienced such violence at a rate
slightly higher than that of Hispanic
women.  No measurable difference in
victimization rates existed between
Hispanics and non-Hispanics younger
than 16 or older than 34. 

Marital status

Age profiles of female victims of 
intimate partner violence show that 
regardless of their marital status, 
women age 20-24 were victimized at 
higher rates than older women. Older 
women were less vulnerable to intimate 
partner violence than younger women, 
although the degree of vulnerability 
differed according to marital status.  
(See the box on page 6 for special 
considerations when examining marital 
status and intimate partner violence.) 

In general, separated females experienced 
intimate partner violence at rates 
significantly higher than women in any 
other marital category.  Separated women 
age 20-24 and 25-34 had the highest annual 
average rates of intimate partner 
victimization (151 and 118 per 1,000 women 
in each age category, respectively).  
Separated females age 50 or older -- an 
age category historically associated with 
relatively low rates of violence in 
the aggregate   were victimized at about 
10 times the rate of divorced women in
the same age category (12.5 versus 
1.2 victimizations per 1,000). 

Overall, divorced women were victimized 
by an intimate partner at the second 
highest rate among the marital categories.  
Divorced females age 20-24 experienced 
an average of 78 intimate partner victimi-
zations per 1,000 females of this age 
between 1993 and 1999. On average 50 females 
age 25-34 per 1,000 experienced violence 
by an intimate partner during the same 
period. (The estimate for divorced women 
age 16-19 is based on fewer than 10 sample
cases.  See Hypothesis testing and the
NCVS on page 11.)

In general, females who never married
sustained violence at rates higher than
those who were married, but lower than
those who were separated.  On average,
20 females per 1,000 age 20-24, and 17
females per 1,000 age 16-19 were
victimized by an intimate, 1993-99. 
These groups experienced statistically
similar rates of victimization and
represented the highest rates for
females who had never married.

Married women reported experiencing
intimate partner violence at rates
lowerthan women in other marital cate-
gories.  Married women age 20-24 had 
8 victimizations per 1,000 women, as
contrasted to 1 per 1,000 among
married women age 50 or older. 

Intimate partner violence rates for
widowed women are not discussed
because the number of cases was not
sufficient for reliable estimates. 

Annual household income  

In general, the age profiles seen in 
the the categories of household income 
resembled the overall age profile. 
Except for women with the lowest
incomes, rates of intimate partner
violence peaked among the younger
women and decreased among older
women.

In general, the lower the annual
household income, the higher the rate 
of intimate partner violence.  Among
females age 16-19, rates of intimate
partner violence for the households
receiving $7,500 or less were at least
twice those of females in the same age
category but at other income levels.  
For women age 20-24 in the lowest
income category, intimate victimization
rates were at least 20% higher than
those in households with a larger
income. 

-----------------------------------
Special considerations when examining
marital status and intimate partner
violence

Caution is warranted in interpreting
intimate partner violence and marital
status in the NCVS because marital
status may be related to a respondent's
willingness or ability to disclose 
violence by an intimate partner.  For 
example, a married woman may not view, 
may not wish to view, or may be unable 
to report the behavior of her partner 
as violent or criminal.  That same woman, 
if separated or divorced, may view or
may be able to report the same behavior
as violent. 

Also, because the NCVS samples
households, it does not capture the
experiences of homeless individuals 
or those living in institutional settings 
such as shelters for homeless or battered
persons.  Nor can it capture the 
experiences of an individual who has 
left a household to escape violence.  The
experiences and estimates of intimate
partner violence in this report reflect 
only those of the individuals residing 
in households.

Marital status is based on the respondent's 
situation at the time of the interview, not 
necessarily at the time of the victimization.  
The survey does not determine whether a 
victim's marital status changed between 
the victimization and the interview. 
 
However, some information may be
gleaned from examining changes in the
marital status of respondents across 
the 6 months from one NCVS interview
to the next. If marital status and 
intimate partner violence were totally 
unrelated, then among those with an 
unchanged marital status, the 
percentages of victims of violence by 
both intimates and non-intimates would 
be about the same. Those percentages 
were not the same. (table below).

Married female victims of intimate
partner violence remained with their
spouse (or were divorced and remarried)
between interviews in significantly lower
percentages than victims of non-intimate 
violence.  Thirty-eight percent of the 
married women who experienced intimate 
partner violence reported being separated 
or divorced in the subsequent interview, 
compared to 2% of women who experienced 
violence by a non-intimate.

Among female victims of intimate partner
violence, 30% of those who were married 
during the previous interview were separated 
at the interview in which they reported 
the victimization. An additional 8% were 
divorced.  Among females reporting a 
victimization by a non-intimate offender, 
1% of women who were married at the time 
of the previous interview were divorced
and 1% were separated.  

While suggestive of a connection between 
intimate partner violence and a change 
in marital status, these findings do not 
provide definitive evidence that intimate 
partner violence caused or was related to 
the change in a woman's marital status 
between two NCVS interviews.

                  Women married at the time
                  of the earlier interview
 
                    Experienced   Experienced
Marital status      intimate      non-intimate
over 6 months       violence      violence
 
Total                  100%          100%
Still married           62            97
Divorced                 8             1
Separated               30             1
 
Note: Percentages may not add to 100% due to 
rounding. Percentages exclude women who did 
not complete two consecutive interviews.
--------------------------------
 
Characteristics of the crime event,
1993-99

Victim-offender relationship 

Fifty-three percent of all victims of
intimate partner violence were victimized
by a current or former boyfriend or
girlfriend.  A third of all victims stated
that the offender was a spouse. 
Fourteen percent described the offender
as an ex-spouse. 

Offenders who committed intimate
partner violence were more often a
boyfriend or girlfriend of younger victims
and a spouse of older victims.  Among
female victims of intimate partner
violence, 94% of those age 16-19 and
70% of those age 20-24 were victimized
by a current or former boyfriend or
girlfriend.

Women age 25-34 who were victimized
by an intimate partner were victimized
by a spouse or by a current or former
boyfriend/girlfriend in similar
percentages (39% and 44%, respectively).  
Women age 35 or older were more likely 
to experience intimate partner violence 
from a spouse than from an ex-spouse or 
from a current or former boyfriend/ 
girlfriend.  Between 1993 and 1999, 69% 
of female victims of intimate partner 
violence age 50 or older were victimized 
by their spouse; an ex-spouse accounted 
for 13%; and a current or former boyfriend 
or girlfriend, 18%.

Presence of weapons 

Most victims of intimate partner violence
do not face an offender who was armed with 
a firearm, knife, or an object like a club 
or bottle.  On average, 81% of female
intimate partner violence victims faced an
unarmed offender, 1993-99.  The percentage 
changes little when taking into account 
the victim's age. For example, between 1993 
and 1999, 79% of females age 25-34, and 87% 
of females age 12-15 faced an offender who
had no weapon.

An average of 15% of intimate partner
violence victims were involved in a
victimization in which the offender had 
a weapon.  Sixteen percent of female
victims age 20-24, 17% of female victims
age 25-34, and 17% of female victims age
50 or older were victimized by an armed
intimate partner between 1993 and 1999. 

Injuries

In general no pattern of injury and age 
of victim was noted between 1993 and
1999.  Overall, 50% of all intimate
partner violence resulted in an injury 
to the victim.  Between 1993 and 1999,
5% of female victims of intimate partner
violence sustained serious injuries, 41%
suffered minor injuries, and 4% were
raped or sexually assaulted and suffered
unspecified injuries. 

Reporting to police

While 54% of all intimate partner
violence against women was reported 
to the police between 1993 and 1999,
adolescent victims and women age 50
or older were less likely than women 
of other ages to state that the
victimizations was reported to police. 
Twenty-eight percent of intimate 
partner violence against females age 
12-15 and 39% of such crimes against 
women age 50 or older were reported to 
the police. In contrast, between 1993 
and 1999, 57% of the violence sustained 
by females age 25-34 and those age 35-
49 was reported to the police.  

Trends in nonfatal violence against
females by intimates, 1993-99

The overall rate of intimate partner
violence against all females decreased
41% from 10 to 6 victimizations per 
1,000 females age 12 or older between 
1993 and 1999.  The estimated number of
violent crimes against all females by
intimate partners decreased from the
1993 level of about 1.1 million to 671,110
in 1999.

There was important variation by age in
trends of intimate partner violence. 
Examining the annual changes in the rate
of violence and applying linear trend 
tests are two methods to illustrate this 
variation. 

Annual changes in intimate partner
violence rates

Females ages 20-24, 25-34, and 35-49
experienced intimate partner violence at
lower rates in 1999 than in 1993. There
were also many year-to-year fluctuations
in rates for the age categories. 

Intimate partner violence against females
age 16-19 fluctuated over the 7 years.
Between 1995 and 1996, intimate partner
violence rates against these females fell. 
In addition, in 1999 rates were marginally
lower than in 1995, the peak year for this
age group.
  
None of the apparent year-to-year shifts 
in intimate partner violence rates for 
females age 20-24 were significant. 
However, rates fell between 1996 and
1999.  The 1999 victimization rate was
lower than the rate in 1993.

After rising between 1993 and 1994, rates
of intimate partner violence against
females age 25-34 remained stable until
1998.  Between 1998 and 1999 rates fell
significantly.  Between 1998 and 1999
rates of intimate partner violence against
females age 25-34 fell. 

For females age 35-49, the rate of intimate 
partner violence in 1993 was higher than 
in every year following, 1994-99. In the 
interim, rates rose slightly between 1996 
and 1998, then fell between 1998 and 
1999.  

Rates of intimate partner violence against
females age 50 or older fell slightly
between 1994 and 1995, and fell marginally 
between 1994 and 1999. 

Rates of intimate partner violence against
females age 12-15 are not discussed
because the number of cases was insufficient 
for reliable estimates. 

Trends and linear trend tests

Another concise way to measure change in 
rates over time is through linear trend
tests.  These tests determine whether a
change over time occurred -- taking into
account interim changes in the rate during
the period of interest. (See Methodology 
for more information.)

Two age categories experienced significant 
declines in rates of intimate violence: 
females age 20-24 and 35-49, 1993-99.  For 
all other age categories, after year-to-
year fluctuations in intimate partner violence 
rates were accounted for, no significant 
declines emerged, 1993-99. 
 
Methodology

Except for homicide data obtained from
the FBI's Uniform Crime Reporting Program, 
this report presents data from the BJS 
National Crime Victimization Survey.   

----------------------------------
Intimate partner violence 
between persons of the same 
gender, 1993-99

Each year between 1993 and 1999, an
average of 142,290 intimate partner
victimizations occurred against males
(not shown in table).  Of that total 
an average of 13,740 -- or 10% -- 
stemmed from intimate partner violence 
between men.
 
In the same period 902,240 intimate
partner victimizations against females
occurred on average each year (not shown 
in table).  Two percent -- 16,900
victimizations -- resulted from intimate
violence between women.  Due to an inadequate 
number of cases, estimates for each year 
are not given.

                   Annual average number of
                   intimate partner victimization
                   between persons of the
                   same gender, 1993-99
Male victims                13,740
Female victims              16,900
-----------------------------------

The NCVS gathers data about crimes
using an ongoing, nationally
representative sample of households 
in the United States.  NCVS data 
include information about crime victims 
(age, gender, race, ethnicity, income, 
and educational level), criminal offenders
(gender, race, approximate age, and
victim-offender relations), and the 
nature of the crime (time and place 
of occurrence, use of weapons, nature 
of injury, and economic consequences). 
NCVS victimization data include incidents 
both reported and not reported to police. 

Between 1993 and 1999 approximately
336,295 households and 651,750
individuals age 12 or older were
interviewed.  For the NCVS data
presented, response rates varied
between 93% and 96% of eligible households, 
and between 89% and 92% of eligible
individuals.

An important consideration in generating
intimate partner violence estimates using
NCVS data is the treatment of "series
data."  Series data are defined as six or
more incidents similar in nature, for which
the victim is unable to furnish details of
each incident separately.  Because no
information for each incident is available,
information on the most recent incident in
the series is collected.  Generally, series
victimizations represent 6% to 7% of all
violent victimizations recorded by the
NCVS, though some variation exists
among the types of crime and victim
characteristics.

Series crimes are problematic in
estimation because how or whether these
victimizations should be combined with
the other crime incidents is unclear.  BJS
continues to study how these types of
victimizations should be handled in our
published estimates.  Currently, series
victimizations are excluded from the
annual BJS estimates but included in
Special  Reports.  In addition, series data
are included for analyses where repeat
victimization is an important aspect of the
subject being analyzed.  This report
includes series victimizations in estimation
of intimate partner violence, counting a
series as one victimization.

Intimate partner relationships involve
current and former spouses and current
and former boy/girlfriends.  Individuals
involved in an intimate partner
relationship may be of the same gender.

Violent acts covered in this report
include murder, rape, sexual assault,
robbery, aggravated assault, and simple
assault.  Overall violent crime 
is a combination of each type of crime.

Hypothesis testing and the NCVS

Standard error computations

Comparisons of estimates discussed in
this report were tested to determine if the
differences were statistically significant. 
Differences described as higher,
lower, or different passed a hypothesis
test at the .05-level of statistical
significance (95%-level of confidence). 
The tested difference was greater than
about twice the standard error of that
difference.  For comparisons of
estimates which were statistically
significant at the 0.10 level
(90%-confidence level), differences are
described as somewhat, marginal, or
slight.  

Caution is required when making
comparisons of estimates not explicitly
discussed in this report.  What may 
appear to be a large difference in
estimates may not test as statistically
significant at the 95%- or even the
90%-confidence level.  Significance
testing calculations were conducted at
BJS  using statistical programs developed
specifically for the NCVS by the U.S.
Census Bureau.  These programs
consider the complex NCVS sample
design when calculating generalized
variance estimates. 

Testing trends in intimate partner 
violence

Unless stated otherwise when a statement
is made describing differences in
estimates between years, it was tested for
significance using a computer program
designed specifically for the NCVS. 
These tests determine whether an
estimate in one year differs from that 
of another, regardless of intervening
estimate variation.  

When a statement is made describing the
increase or decrease of a linear trend, 
it was tested using a linear trend test,
comparing the slope of the trend to a
slope of zero.  This test takes into 
account estimate variation in intervening 
years. 

The linear trend test is a regression
equation using time as the independent
variable, and the estimate of victimization
as the dependent variable.  A regression
coefficient (b) and its corresponding
standard error (F) are computed.  Next a
t-statistic -- the ratio b/F -- is 
calculated.  If the t-statistic is greater 
than 1.96 for a two-tailed test, the slope 
is different from zero, and if the t-
statistic is greater than 1.645 for a 
two-tailed test, the slope is slightly 
different from zero.  If the t-statistic
is less than the critical value, the 
trend of the estimates does not differ 
significantly from a flat line.

Estimates based on 10 or fewer sample
cases have high relative standard errors. 
Because calculated standard errors for
such estimates may not be accurate, care
should be taken when comparing estimates 
based on 10 or fewer cases to other 
estimates.  It is not advisable to
make comparisons between estimates
when both are based on 10 or fewer
sample cases. 

-----------------------------------
Definitions of intimate partner 

Intimate partner relationships involve
current spouses, former spouses, current 
boy/girlfriends, or former boy/girlfriends.  
Individuals involved in an intimate 
partner relationship may be of the same 
gender.  The FBI, through the Supplementary 
Homicide Reports (SHR), and BJS, using 
the NCVS, gather information about the 
victim's and offender's relationship, 
using different relationship categories, 
as shown below.

              NCVS            SHR
              categories      categories
 
Intimate      Spouse          Husband/wife
              Ex-spouse       Common-law
                              husband or wife
              Boyfriend/      Ex-husband/
              girlfriend      ex-wife
              Ex-girlfriend/  Boyfriend/
              ex-boyfriend    girlfriend
                              Homosexual
                              relationship
------------------------------------
    
This report and additional data,
analyses, and graphs about criminal
victimization in the United States 
are available on the Internet at

http://www.ojp.usdoj.gov/bjs/

Data presented in this report can be
obtained from the National Archive of
Criminal Justice Data at the University 
of Michigan, 1-800-999-0960.  The 
archive can also be accessed through 
the BJS Web site.  When at the archive 
site, search for dataset ICPSR 6406.

The Bureau of Justice Statistics is the
statistical agency of the U.S. Department 
of Justice. Lawrence A. Greenfeld is 
acting director.

Callie M. Rennison, BJS Statistician,
wrote this report under the supervision
of Michael Rand.  Marianne Zawitz, BJS
Statistician, provided homicide data. 
Cathy Maston provided statistical
review.  Tom Hester and Ellen Goldberg
produced and edited the report.  Jayne
Robinson administered final production.

October 2001, NCJ 187635

End of file
10/18/01 ih

revised 
11/28/01 th